JPS5865674A - Printer - Google Patents

Abstract

PURPOSE:To obtain the printer characterized by high speed, high resolution, and inexpensive running costs, in so called a line printer, by employing an electronic photograph recording system wherein an endless belt shaped recording body is used, and providing an almost linear recording paper path. CONSTITUTION:At the central part of the printer 1, the endless belt shaped recording body 11 is hooked around a pair of belt rollers 12 and 13. The recording body 11 is an electronic photographing light sensitive body wherein an inorganic or organic light conductive body is provided on a base film. The surface of the recording body 11 is uniformly charged into a specified polarity by an electric charger 14. Then light including the data of picture to be recorded is irradiated from an exposing device 15, and an electrostatic latent image is formed on the recording body 11. Thereafter it is developed by the toner in a developing device 16 and transferred to recording paper 24 by a transfer charger 19. The tansferred to recording paper 24 by a transfer charger 19. The transferred toner image on recording paper 24 is fixed in a fixing device 20. The recording paper 24 is discharged to a recording paper receiver 10 by a paper discharging roller 25.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a printer as a peripheral terminal device for a computer, a printer similar to a so-called line printer.

The reality is that hexagonal devices connected to computers are becoming faster and faster.Therefore, printers as output devices are also required to be faster. Of course, it is also required to be small, requiring a small installation space, and easy to maintain.Even if high-speed printing can be achieved,
If the device is the grand prize and it takes time to solve a problem when it occurs, it cannot be said to be a substantial increase in speed. Another technical issue is that running costs are required to be low.

The present invention has been made in response to the various technical problems described above, and provides a printer that can stably obtain recorded images with relatively high resolution and high resolution, has low running costs, and is small and configured. The purpose is to provide a printer that is simple and easy to maintain.

The object of the present invention is to provide a recording body unit including an endless belt-like recording body that is wound around a plurality of belt rollers and rotates in one direction, a charging device that uniformly charges the recording body, and a charging device. a developing unit including a lightless means for forming an electrostatic latent image by exposing the recording medium to light, and a developing roller for supplying a developer to the recording medium to visualize the electrostatic latent image, and forming a visible image. a paper feeding device that separates and feeds out the stacked recording sheets one by one to bring the recording paper into close contact with the recorded body; a transfer device that transfers a visible image onto the recording paper that is brought into close contact with the recording body; A fixing device that fixes the visible image onto the recording paper, a paper discharge device that discharges the fixed recording paper to the outside of the machine, a static eliminator that removes the electric charge remaining on the recording medium after the visible image has been transferred, and a A cleaning device that comes into contact with the surface of the recording medium after image transfer to remove developer remaining on the surface; a driving means that drives each device including the recording body unit; and an operation of each device including the driving device. The paper feeding device includes a control means for controlling the paper feeding device, so that the recording paper sent out from the paper feeding device is ejected outside the machine through a nearly straight recording paper path.
This is achieved by a printer characterized in that it is equipped with a recording body unit, a transfer device, and a fixing device.

According to the printer of the present invention, since it uses an electrophotographic method, it is possible to obtain recorded images with high resolution, and since it uses a visible image transfer method, plain paper can be used as the recording paper, so running costs are reduced. is low. In addition, since the recording body is formed into an endless belt shape,
Since the device can be made small in size and the recording paper path including the recording medium is configured in a substantially straight line, maintenance is easy and troubles with the recording paper can be suppressed as much as possible.

The printer discharges one sheet of recording paper every - number of recording operations. In other words, the recording paper goes through various processes, and if the path is configured to be close to a straight line,
Troubles caused by recording paper such as paper jams can be avoided as much as possible.

The printer of the present invention has a number of other features such as a simplified configuration and ease of maintenance, which will become clear in the description of the embodiments.

Hereinafter, the present invention will be explained in detail with reference to illustrated embodiments.

FIG. 1 shows the external appearance of the printer of the present invention, with reference numeral 1
indicates the entire printer. On the front of printer 1,
A power switch 311 is provided.

Also, on the front of the printer 1, the recording paper tray 3 is indicated by the arrow a.
It is removably attached in the direction shown.

The lid 4 of the tray 3 can be opened and closed in the direction of arrow C while the tray is attached to the printer body.

Furthermore, on the front of the printer l, there is a recording medium, which will be described in detail later.
A developing unit 5 is attached so as to be freely drawn out in the direction of the arrow. Although this unit 5 can be pulled out a certain length or completely out of the printer, FIG. 1 shows the unit 5 in its fully pushed position into the printer body. In the figure, reference numeral 6 indicates a handhold portion of the unit 5. Inside the transparent cover 7 on the front side of the printer 1, a pause button, a reset button, an indicator lamp, etc. (all not shown) are housed. The side plate 8 of the printer body and a portion 9 of the top cover can be removed from the printer body. A recording paper receiver 10 is provided at the rear of the printer to receive recording paper discharged outside the machine.

The printer of the present invention utilizes an electrophotographic dry development visible image transfer method, and the internal structure thereof is summarized in the second section.
This will be explained based on the diagram.

Approximately at the center of the printer 1, an endless belt-shaped recording medium 11 is placed around a pair of belt rollers 12 and 13. Among the belt rollers 12 and 13, the roller 12 is a driven roller, and the belt roller 13 is a driving roller.
It is rotated in the direction of the arrow by a drive system to be described later. The recording medium 11 is an electrophotographic photoreceptor in which an inorganic or organic photoconductor is provided on a base film.

Various devices are arranged around the recording medium 11.

To explain them in terms of the clockwise rotation direction of the recording medium 11, reference numeral 14 is a charger, 15 is an exposure device, 16 is a developing device, 17 is a paper feed roller, 18 is a pair of transport rollers, and 15 is a developing device. 19 is a transfer charger, 20 is a fixing device, 21 is a static eliminator, and 22 is a cleaning device.To briefly explain the functions of this printer, first, the recording medium 1
1 is irradiated with light containing information of an image to be recorded by a charger 14. As a result, the charges on the recording medium 11 are selectively dissipated, and an electrostatic latent image corresponding to the image to be recorded is formed thereon. This electrostatic latent image is then visualized by being supplied with a developing agent consisting of colored fine particles called toner from the developing device 16, and a toner image appears there. This toner image is superimposed at the position of the transfer charger 19 on the recording paper 24 fed from the recording paper tray 3 by the paper feed roller 17 and the pair of transport rollers 18 in synchronization with the image formation on the recording medium 11, and is transferred. By being charged by the charger 19, the image is transferred onto the recording paper 24. The recording paper 24 is then separated from the recording body 11 and enters the fixing device 20, where the transferred toner image is fixed, and the recording paper 24 is discharged by a pair of paper discharge rollers 25 to the recording paper receiver 1O. On the other hand, the potential remaining on the surface of the recording medium 11 is removed by the static eliminator 2.
1, residual toner remaining after transfer is removed by a cleaning device 22.

The specific configuration of each device of this printer will be explained.

A feature of this apparatus is that the recording medium 11 and the developing device 16 are each assembled into a unit. That is, as shown in FIG. 5, the recording body unit 23 consists of a recording body 11, rollers 12 and 13 that support and drive this, and support plates 26 that rotatably support both ends of both rollers. It has become.

As shown in FIGS. 4, 8, and 12, the drive roller 13 is rotatably supported at one end of the support plate 26 by a shaft 38 fitted with a bearing 46. An endless belt-shaped recording medium 11 is wound between the driving roller 13, which rotates at a fixed position, and a driven roller 12, which will be described next.

The recording body 11 is formed to be slightly longer than the length of the recording paper, and when the main switch described later is on, the seam X of the recording body 11 is formed as shown in FIG. It is located at the top.

When the main switch is off, the seam X of the recording medium 11 is located below the charger 14, as shown in FIG. 78(1). Control of the position of the recording body 11 will be described later.

The driven roller 12 is pressed outward by a spring 27 provided on the support plate 26 to apply tension to the recording medium 11 . FIG. 6 shows an example of a recording medium tension applying mechanism.

A bearing 43 having a groove 42 on the outer periphery is fitted onto the shaft 12α of the driven roller 12. A portion of the outer circumference of the bearing 43 has a surface 43α that receives one end of the spring 27.
is formed. On the other hand, the support plate 26 is formed with a pair of support pieces 44, 44 that fit into the grooves 42 of the bearing 43, and a spring stop 45 that projects triangularly between the support pieces. The driven roller 12, which has a bearing 43 fitted into the shaft 12a, moves toward the support plate 2 while the groove 42 of the bearing is guided by the support piece 44 of the support plate 26.
6, the wire holder is connected to the surface 43α and the spring stopper 45.
A spring 27 is attached between the two. Therefore, the tension F is applied to the recording body 11 in FIG. 5 by the spring 27 via the roller 12, thereby giving it good flatness.

The recording medium 11 wound between the belt rollers needs to be replaced with a new one due to deterioration or damage. Furthermore, if unnecessary tension is applied to the recording body when the recording body unit 23 is not attached to the printer main body, for example while being stored in a warehouse or being transported, it may cause the recording body to wrap around the belt roller. A change in shape occurs in which the part becomes curly. Also, high temperature and high humidity during storage and transportation.

If tension is applied for a long time under adverse environmental conditions such as low temperatures, the recording medium may undergo expansion/contraction, surface cranking, and characteristic deterioration.

Therefore, when replacing, storing, or transporting a recording medium, a tension release mechanism is provided to release the action of the above-described tension applying mechanism to solve the above problem.

15 and 16, a lever guide hole 47 in the shape of an inverted character is bored in the support plate 26. As shown in FIGS.

This hole 47 consists of a portion 47α parallel to the direction in which tension is applied to the recording medium 11, and a locking portion 47b that intersects this portion 47α at an angle smaller than a right angle. However, one bent end 48α of the release lever 48 is fitted into the C-guide hole 47. One end 4812 of this lever is attached to the support plate 26
stands out from The other end 48b of the release lever 48 is curved and surrounds the outer periphery of the bearing 43 fitted to the shaft 12 (Z) of the driven roller 12.

Then, as shown in FIG. 16, one end 48 of the release lever
When α is located at the portion 47α of the hole 47, the other end 48h of the lever does not impede the action of the spring 27 to apply tension to the recording medium 11 in any way.

When it is desired to release the tension on the recording medium, such as when replacing the recording medium, as shown in FIG. After overflowing and moving, attach this end to the locking part 4
Position it at 7h. At this time, the other end 4 of the release lever 48
8b moves the bearing 43 to the right in the figure, so the driven roller 12 and the driving roller 13 (not shown)
The distance between the axes is shortened by approximately the length l1, and the tension on the recording medium 11 is released. Therefore, the recording body 11 is kept in a relaxed state as shown in FIG. 17, and can be easily attached and detached from between the belt rollers and replaced. When the release lever 48 is moved to the position shown in FIG. 16 after replacement, tension is applied to the recording medium 11 by the spring 27. The release lever 48 shown in FIG. 15 is formed by bending a small-diameter round bar, but like the release lever 48A- shown in FIG.
8AcL and a locking pin 48Ab made of a bar. In addition, in FIGS. 5 and 7, the support plate 26
A hole 26α formed approximately in the middle of the release lever 4
8 and when the recording body unit 23 is set in the receiving portion 35 and the recording body/developing device unit 5 (see FIG. 7) is assembled, the finger rest is provided in the hole.

As shown in FIG. 5, the support plate 26 has a top plate 28 on its upper part, and supports the lower surface of the upper extending portion 11α of the recording medium 11. At the lower part of the support plate 26, two protrusions 29 and 30 are provided so as to protrude from the lower surface of the lower extending portion 11h of the recording medium 11. The developing unit 31 includes a container 33 with a lid 33a containing a developing toner 32, and a developing sleeve 34 rotatably supported at the lower part of the container 33. The side plates and bottom plate of the developer container 33 extend perpendicularly from the portion supporting the developer sleeve 34 to form a receiving portion 35 that supports the recording unit 23. A groove 3 is formed in the vicinity of the developing sleeve 34 on both side plates 36 of the receiver part 35, perpendicular to the longitudinal direction of the receiver part.
7 is formed, and the shaft 38 of the recording body drive roller 13 of the recording body unit 23 is inserted into this groove 37, and the recording body 11 is positioned with respect to the developing sleeve 34.

The recording body unit 23 is connected to the receiving part 3 of the developing unit 31.
Since it is simply placed on the bottom plate 39 of No. 5, and the shaft 38 is simply inserted into the groove 37, movement in the left and right direction is restricted, but movement in the upward direction is free.

When the recording body unit 23 is placed on the bottom plate 39 of the support section 35, the support plate 26 of the recording body unit 23,
Since only the lower protrusions 29 and 30 touch the bottom plate 39, the recording medium 11 will not be damaged. Furthermore, a groove 40 is provided at the tip of the receiving portion 35 in parallel thereto, and this serves for positioning when the developing device unit 31 is attached to the main body of the apparatus. The rear ends of the side plates 36 and 36 are connected and reinforced by stays 73, as shown in FIGS. 2 and 4.

FIG. 7 shows a state in which the recording unit 23 is assembled to the developing unit 31. In this figure, a bearing 41 is attached to the shaft 38 of the recording medium drive roller 13, and this bearing 41 is engaged with a groove 37 in the receiver of the developing unit 31. Of course, the present invention can be applied to other places in light of known techniques.

When the recording body unit 23 is set on the receiver 35, if a finger touches the surface of the recording body, the photosensitive characteristics of that portion will change. Therefore, the unit 23 is held by hooking the fingers into the holes 261Z, and a notch 36α is formed in the side plate 36 to allow the fingers to escape during the above-mentioned setting. , developer unit) 31, a first member 49 and a second member 50 are provided on both side plates 36 of the receiving portion 35, respectively. 1st
The member 49 is fixed to the side plate 36 with screws 51, and has a pair of spacers 52 with a cross-sectional shape as shown in FIG. The upper end of the regulating surface of the spacer 52 is cut off and serves as a guide surface 52h when the recording unit 23 is mounted.

In the illustrated example, the second member 50 has the same shape as the first member 49, and is attached to the side plate by screws 53.
6, and the spacers 52.6 are fixed to both ends thereof.
It consists of a guide member 54 formed with guide portions 54α, 54α opposite to the guide member 52, and an elastic member 55 fixed to the side plate 36 in alignment with the guide member 54. Elastic member 55
In the illustrated example, a pair are provided. Of the first member 49, guide member 54, and elastic member 55, at least the elastic member 55 is made of a conductive material, and the receiver is electrically connected to the portion 35. The receiving portion 35 is grounded to the entire recording apparatus via a guide plate 56 (see FIG. 9). Although the elastic member 55 is formed of a metal plate spring in the illustrated example, it may be a metal coil spring.

The position of the recording unit 23 with respect to the receiver portion 35 is determined by the width WC of the spacer 52, and this width WC is
It is determined by the relative relationship with other various devices installed around the recording medium 11. The width between the support plates 26 and 26 of the recording unit 23 is Wa, and the width between the regulating surface 52a and the tip 55α of the elastic member in the free state is W.
When b, the elastic member 55 is set so that Wa>Wb.
The protrusion amount is set.

Furthermore, the distance between the regulating surface 52fZ and the guide portion 54a is set to be larger than the width Wα by a gap WCL.

This gap Wd is set to a necessary and sufficient value so that the recording unit 23 can be easily attached to and detached from the receiver part 35.

Now, as shown in FIG. 11, when the recording unit 23 is dropped from above the receiver part 35, the unit is guided by the pair of support plates 26, 26 by the guide surface 52b and the guide part 54α. As shown in FIG. 12, one support plate 26
is elastically pushed and moved by the elastic member 55, so that the other support plate 26 is brought into contact with the regulating surface 52a and mounted. That is, the recording unit 23 has the elastic member 55
While bending, drop the protrusion 29.30 (5th
(see figure) are abutted against the bottom plate 39, and one support plate 26 is elastically pressed against the regulating surface 52α to be positioned.

Therefore, in the width direction of the recording body unit 23c, the endless bell-shaped recording body 11°, its -side surface is aligned with the regulating surface 52α.
At the same time, the receiver is held in electrical communication with the portion 35 while being positioned by abutting the other side against the conductive elastic member 55 .

When removing the developer unit support unit 35 from the support unit 35 for the recording body unit, the elastic member 55 is of course bent, and it can be attached and detached very easily.

In the embodiment shown in FIGS. 11 and 12, a fixed spacer 52 having a regulating surface 52α and another spacer (guide member 54) having a guide portion are provided, and this guide member has elasticity. Although the member 55 is provided, one of the spacers (guide member 54) may be omitted and the second member may be constituted by only the elastic member 55. In this case, it goes without saying that the elastic member 55 may be made electrically conductive, and is desirably provided at a position where it comes into contact with the substantially central portion of the support plate 26 (in the moving direction of the recording medium 11).

Even with such a simple configuration, the position of the recording medium support member (support plate 26) is regulated in the width direction of the recording medium by two regulating surfaces 52a+52α and one elastic regulating portion. At the same time, the receiver also maintains electrical connection with the part.

The developing unit 31 holding such a recording body unit 23 is attached to the main unit so that it can be inserted into and pulled out from the main unit. As shown in FIG. 9, the main unit includes a guide plate 57 for guiding the upper part of the container 33 of the developing unit 31 and a guide plate 56 for guiding the lower bottom plate 39.
are attached, and the developer unit (31) is inserted into the main unit in defiance of these. The main unit is also provided with guide plates 58 for guiding both sides of the developing unit 31, as shown in FIG. will be done. The main unit is further provided with a pin 59 protruding from the side plate 6o of the main unit for positioning the developing unit 31 in the insertion direction, and this pin 59 is inserted into the groove 40 at the tip of the developing unit (see FIG. 5). The position of the current device unit 31 in the insertion direction is determined by engaging with it. The side plates 60, 67 (see FIG. 8) of the main device further support bearings 42 of the rotation shaft 38 of the drive roller 13 and the rotation shaft 12α of the driven roller 12 in the recording unit when these are inserted. 61 and 62 are provided at predetermined positions, respectively. This bracket is for vertically positioning the recording medium 11 via each roller. Thereby, each roller 12, 13 and the developing sleeve 34 are aligned substantially in a straight line parallel to the insertion direction.

The bracket 62 is attached to the side plate 60.67 (
(see Fig. 4), but when constructing a belt deviation correction mechanism, at least the bracket 62 provided on the side plate 6o needs to be provided swingably without being fixed. .

This belt deviation correction mechanism will be described later.

Since this supporting device is provided with such various positioning means, the recording body/developing unit 5 (see FIG. 7) consisting of the recording body unit, the unit 23, and the developing unit 31 is placed in the main unit. By simply inserting the device into a predetermined position, the mutual positional relationship with other members within the device body and the device can be securely and easily secured. Furthermore, by pulling out the developing device unit 31 from the main body of the apparatus, it is extremely easy to replenish toner in the developing container 33 or replace the recording medium 11, as required.

FIG. 13 shows the drive system in this support device. The rollers 12 and 13 that support and drive the recording medium 11 and the developing sleeve 34 are arranged in a substantially straight line parallel to the direction of insertion and withdrawal of the developing unit 31, and the driving source of the main body of the apparatus is arranged in a direction substantially perpendicular to this. A power transmission gear 63 connected to the drive roller 13 is disposed, and a drive gear 64 fixed to the rotating shaft 38 of the drive roller 13 meshes with the drive gear 63 . Although the illustrated power transmission gear 63 meshes with the lower part of the drive gear 64, it may mesh with the upper part of the drive gear 64. The drive gear 64 also meshes with a driven gear 66 fixed to the rotating shaft 65 of the developing sleeve 34, so that the power from the drive source of the main body of the apparatus is transmitted from the gear 63 to the driven gear 66.
transmitted to. FIG. 14 shows this state in a perspective view. By configuring the drive system in this manner, the developing device unit 31 can be easily inserted and withdrawn, and power transmission when inserted is ensured.

In this way, since the recording medium and the developing device are assembled into units, they can be easily attached to and detached from the main unit, and their positions can be reliably regulated. Although the gap between the recording medium, the developing sleeve, each charger, etc. must be maintained at 7 vias, according to this invention,
Even though the recording medium and developing device are removable from the main unit, the gap between them can be easily and accurately positioned using multiple positioning means, eliminating the need for position adjustment and eliminating the risk of position fluctuation. . Further, there is no need to provide a large opening as in conventional devices, and it is possible to replace the recording medium, perform other repairs, replenish developer, etc. using only a small opening and a simple guide means. Furthermore, since the recording medium and developing device are integrated into a unit, the configuration is small and simple, and the entire recording medium can be easily replaced. The surface will not be contaminated with developer. Further, since the drive system is arranged so that the unit can be easily attached and detached, and the power is reliably transmitted, there is no problem in attaching and detaching the unit.

Further, the endless belt-shaped recording medium has its upper extending portion 11α guided by a top plate 28 of a support plate. Therefore, static electricity is generated due to friction between the two. This static electricity appears as a tension phenomenon on the top plate 28 of the recording medium, resulting in an increase in driving load and, in turn, unevenness in the recording medium feeding speed due to the gap between the drive roller 13 and the recording medium. Therefore, the recording medium support plate must be reliably grounded.

The recording medium 11 consists of a paste layer made of flexible rubber or synthetic resin, a conductive layer made of an aluminum thin film layer deposited on top of this, and a layer above this conductive layer. Note that an insulating layer may be formed to cover the photoconductive layer.

In order to obtain a clear image, an accurate electrostatic latent image must be formed that corresponds to the image information.

To this end, on the surface of the recording medium that is uniformly charged by the corona discharge of the charging charger 14 (see Figure 2), conductivity is generated only at the exposed areas, and the potential of the area is reduced to the ground potential (zero) as much as possible. bolt). Therefore, the side edges in the width direction of the recording body 11 are peeled off to expose the conductive layer, and a grounding brush is brought into contact with this portion. A reinforcing agent may be applied to this exposed portion.

In FIG. 8, an exposed portion 68 in which a conductive layer is exposed is formed at one side edge of the recording body 11. As shown in FIG. This irises part 68
The free end of a grounding brush 69 made of conductive fibers is brought into contact with the grounding brush 69 . The grounding brush 69 is a bracket) 7
0 to the side plate 67 in a conductive manner. In the moving direction of the recording body 11, the grounding bluff 69 is
As shown in FIG. 2, it is provided at a portion that is on the tension side of the recording medium 1 and moves linearly close to the drive roller 13. The following problems were behind the selection of this installation location. When the grounding brush is brought into contact with the slack side of the endless belt-shaped recording medium 11, the contact state changes over time due to the waving of the rotating belt, and the impedance of the conductive path changes due to the change in contact resistance. The recording medium is most stable when it is wrapped around the belt roller, but if the brush is brought into contact with a curved area, the contact angle between each brush fiber and the recording medium will be different. , stable electrical contact cannot be obtained. Further, if the recording body unit 23 is detachable from the apparatus main body and is integrated with the developing unit 31, the part of the recording body unit 23 must be used for winding around the driven roller 12.

However, since the roller 12 is movable in order to apply tension to the recording medium, the relative distance between the grounding plan and the recording medium is not constant, and a stable conductive path cannot be formed.

Therefore, the stable position of the endless belt-shaped recording medium is near the drive roller 13, where the shaft 38 rotates at a fixed position, and is on the so-called tension side where tension is applied. On the tension side 1] α, the belt becomes straight and vibrations caused by rotation are minimized. It will be understood that for this reason, the relative position between the recording body 11 and the grounding brush is always kept constant, and an extremely stable conductive path can be maintained.

Furthermore, a sub-scanning synchronization mark 71 is provided on the other side edge of the recording body 11, as shown in FIG.

This synchronization mark has an important meaning in the 7-can of the device, and its function will be described later. Further, in FIG. 8, a sub-scan synchronization detector 72 for reading the sub-scan synchronization counter 71 is fixedly provided on the side plate 6o, facing the sub-scan synchronization counter 71.

When an endless belt-like recording medium is driven by a roller, the tension applied to the belt-like recording medium on the roller may be caused by an error between both ends in the axial direction of the roller, or the axes of rollers that should be parallel to each other. Due to the occurrence of a parallel error in the belt, a phenomenon in which the recording medium moves in a direction perpendicular to the driving direction, that is, a meandering and shifting phenomenon of the belt may occur. If this phenomenon occurs, the image formed on the recording medium or the image transferred to the paper will be biased, so this phenomenon should be prevented.

For this purpose, the following devices are conventionally known.

Firstly, a roller for supporting and driving an endless belt-like recording medium is provided with a flange for regulating the end of the recording medium, thereby restricting meandering and shifting of the belt. At least one of the rollers for supporting and driving the recording medium is equipped with a self-aligning mechanism, that is, when the belt shifts, the belt moves in the opposite direction to the shifting direction by using the shifting force. This device has a self-aligning mechanism that changes the inclination of the self-aligning axis. Here, in the first apparatus, stress is always generated at the end of the belt-shaped recording medium due to the shifting force of the recording medium.

The stress thus generated causes deformation at the end of the belt-shaped recording medium, thereby significantly reducing the durability of the belt and the reliability of the recording apparatus. Therefore, when using this apparatus, it is necessary to increase the strength of the belt-shaped recording medium against deformation at the end of the belt, or to weaken the shifting force of the belt. However, when the base of the belt-shaped recording medium is thickened, problems such as a decrease in the adhesion strength of the recording layer attached to the base and an increase in belt tension due to an increase in bending stress are undesirable. In addition, when reducing the belt bias force,
Delicate adjustment of the belt tension is required, so this recording device must be highly accurate and complex. On the other hand, in the second device, a high-precision roller mechanism is required in order to ensure self-aligning operation, making this device complicated, large, and expensive. .

The present invention eliminates the above-mentioned drawbacks by attaching to the recording medium a belt deviation correction mechanism having deviation detection means for detecting deviation of the belt and deviation control means for correcting deviation of the belt.

Hereinafter, the correction mechanism will be explained in detail by being divided into the shift detection means and the shift control means.

First, the deviation detection means based on the first idea will be explained. The first idea is to detect the shift of an endless belt-shaped recording medium by combining a photointerrupter that has a light source and a light receiving element, and a light shielding member that is movable to block the optical path between the light source and the light receiving element. It is something to do.

FIG. 20 shows the first deviation detection means based on the first idea above.
It is a figure showing an example. This detection means is shown in Figures 2 and 4.
As shown by the reference numeral 74 in the figure, an area (hereinafter referred to as
curvature area).

In the same figure, the detection means 74 has the following configuration. A support member 76 is attached to the bracket 75 in front of the recording medium 11, and the support member 76 rotatably supports the detection filler 77 at its fulcrum 76α. The detection filler 77 is configured with a contact piece 77a on one side of the recording body 11 side and a light shielding piece 77b on the other side with the support member 76 as a boundary, and this contact piece 77α
is arranged so that its tip can come into contact with the end of the recording body 11. Further, a photo interrupter 78 is arranged within the rotation area of the light shielding piece 77h.

FIG. 21 is a sectional view showing the photointerrupter 78 along the line XX in FIG. 20. In the figure, a photointerrupter 78 has a light source 79 and a light receiving element 80, and this photointerrupter 78 generates an output signal corresponding to the amount of light emitted from the light source 79 and received by the light receiving element 80. Further, as shown in the figure, the light shielding piece 77b is connected to the light source 79.
and the light receiving element 80.

An L-shaped stopper 81 is attached to the bracket 75 below the support member 76 to restrict rotation of the contact piece 77α in the counterclockwise direction in the figure. Dominant bodies such as torsion coil springs and leaf springs that give a counterclockwise rotational habit (not shown)
is installed.

Therefore, as long as the contact piece 77α does not come into contact with the edge 11C of the recording medium 11, the contact piece 77α is pressed against the stopper 81 by the action of the tension body.

The operating state of the shift detecting means 74 having the above configuration will be explained below. During normal recording work,
The recording body 11 moves in the direction of arrow A from a position d shown by a solid line in FIG. In this state, the contact piece 77Z does not come into contact with the edge 11c of the recording medium 11, and therefore the light shielding piece 77h
The light receiving element 8 of the photo interrupter 78 is also connected from the light source 79 to the light receiving element 8.
The optical path leading to zero is not blocked. Therefore, the photointerrupter 78 generates an output signal corresponding to the amount of light passing through the optical path. Next, when a shift phenomenon occurs in the recording body 11 in the C direction and the recording body 11 reaches a position e shown by a broken line in the figure, the contact piece 77d first moves the recording body 11 at a position (3) shown by a solid line in the figure. Then, as the recording medium 11 moves in the C direction, the fulcrum 7f
The contact piece 77α is rotated in the clockwise direction, and as a result, the contact piece 77α reaches the position ■ shown by the broken line in the figure. In addition, the contact piece 77α
At the same time as the light shielding piece 77h rotates, the light shielding piece 77h also rotates from the solid line position (■') to the broken line position (2') in the figure, thereby blocking the optical path leading to the position (2). is the photo interrupter 78 whose optical path is blocked.
causes a change in the output signal. That is, the recording body 11
The deviation in the C direction is detected as a change in the output signal of the photointerrupter 78.

The above explanation is for the case where the recording body 11 shifts in the C direction, but the recording body 11 has a side edge 11d (see FIG. 4) that is paired with the edge 11C. A detection means (see FIG. 4) which is the same as the above-mentioned shift detection means 74 is provided in advance, and when the recording medium 11 shifts in the direction opposite to the C direction, that is, in the D direction in the figure, the other one is detected. The detection means 74 serves to detect belt drift.

Further, a change in the output signal of the photointerrupter in the side deviation detection means is transmitted to belt deviation control means (described later) via a control circuit (described later), and the deviation of the belt-like recording medium 11 is transmitted to the belt deviation control means (described later). is corrected as appropriate.

The shift detecting means is arranged to face the curvature area of the endless belt-like recording medium 11, and the reason for this will be described below based on the drawings. FIG. 22 shows an endless belt-like recording medium 11 and rollers 12 and 13 that support the recording medium 11.
It shows. In the figure, the area indicated by arrow E is the curvature area of the belt mentioned above, and the area between this curvature area E and the curvature area E1 corresponding to the other roller 13, that is, the area indicated by arrows G, G. Since the recording medium 11 has a linear shape, this region G + G 1 is referred to as the linear region of the recording medium. Here, when a force is applied from the end of the recording body 11 in a direction in which the recording body 11 shifts, that is, in a direction perpendicular to the driving direction A of the recording body 11, the recording body 11 is easily deformed in the linear region Gr G1. However, in the curvature region E, the recording medium 11 is difficult to deform. Therefore, the area where the contact piece should be brought into contact is preferably the curvature area E, where deformation is less likely to occur compared to the straight line areas G and G1.By doing so, the rotation of the contact piece is stabilized, and recording is possible. The influence on the end deformation of the body 11 is also reduced.

FIG. 23 is a diagram showing a second embodiment of the intrusion detection means based on the first idea, and the differences from the first embodiment shown in FIG. 20 are as follows. In other words, the shift detection means 82
In the rotation area of the light shielding piece 77b, there are two
photo interrupter 83α.

83h is provided, and furthermore, the stopper 81 in the first embodiment is omitted. With this configuration, the contact piece 77α
is in constant contact with the edge of the recording medium 11 under the action of a tension body (not shown), and rotates as the edge moves. For example, when the end of the recording body 11 moves from a position d shown by a solid line to a position e shown by a broken line, the contact piece 77α
Accordingly, from the position shown by the solid line■ to the position shown by the dashed line■
When the recording medium 11 moves to the position indicated by the four-dot chain line f, the contact piece 77a rotates to the position indicated by the one-dot chain line ■.

Furthermore, at the same time that the contact piece 77 (L) rotates to position ■ or position ■, the light shielding piece 77h rotates to position ■' or position ■', respectively. In this case, the photointerrupters 83a and 83h are as follows. That is, when the light-shielding piece 77h reaches the position ■', the photo-interrupter 83α is blocked from its optical path, and when the light-shielding piece 77h reaches the position ■', the photo-interrupter 83h interrupts its optical path. is blocked.

The configuration other than the above is the same as that of the first embodiment shown in FIG. 20, and the same components are indicated by the same reference numerals.

In this embodiment, during normal recording work, the recording medium 1
1 moves in the direction of arrow A at position d.

In this state, the light shielding piece 77b does not block any of the optical paths of the photointerrupters 83a and 83b, and therefore the photointerrupters 83α and 83h generate output signals corresponding to the amount of light flowing through the optical paths. Next, a shift phenomenon occurs in the recording body 11 in the C direction, and the recording body 11 is moved to the position e.
When the contact piece 77a moves to the position (2), the contact piece 77a rotates to the position (2), and at the same time the light shielding piece 77h rotates to the position (2'). The thus rotated light blocking piece 77h blocks the optical path of the photointerrupter 83α, resulting in a change in the output signal of the photointerrupter 83Z. On the other hand, when a shift phenomenon occurs in the recording medium 11 in the D direction and the recording medium 11 moves to position f, the contact piece 77α rotates to position 2, and at the same time, the light shielding piece 77b rotates to position m'. The thus rotated light blocking piece 77h blocks the optical path of the photointerrupter 83h, thereby changing its output signal.

That is, the shift of the recording medium 11 in the C direction causes a change in the output signal of the photointerrupter 83α.
The shift in the D direction is detected as a change in the output signal of the photointerrupter 83b.

As described above, this embodiment is advantageous because the deviation of the recording medium 11 in the C direction and the D direction can be detected by one deviation detection means 82.

Incidentally, changes in the output signals of the photo-interrupters 83α and 83b are transmitted to belt deviation control means, which will be described later, in the same manner as in the first embodiment.

FIG. 24 is a diagram showing a third embodiment of the welfare-oriented detection means,
In the figure, the shift detection means 84 has the following configuration. In front of the curvature region of the recording body 11 corresponding to the roller 12 (on the left side in the figure), there is a slide part extending in the axial direction of the roller 12 and having a length slightly longer than the width of the recording body 11. 85 are provided.

This slide par 85 is located in the center and in front (left side in the figure).
It has a light-shielding piece 86 that protrudes toward, and further has contact pieces 87α and 87b that protrude rearward (to the right in the figure) at both ends. In addition, this slide no. (-85) is provided with elongated holes 85a and 85A that are long in the axial direction of the roller 12.
Pins 88α and 88h are fixed on each long side.
is loaded. These long holes 85a.

85b and the pins 88a, 88b, the slider 85 is parallel to the roller 12 and the elongated hole 85α.

It can move by a length of 85 hours. Arrow C' and arrow D' in the figure indicate the direction of movement of this slide <-85. The contact pieces 87α and 87h are connected to the recording body 1
1 has such a length that it can come into contact with the edge 11C or 11d of the recording medium 11 when it moves in the direction of arrow C or in the direction indicated by the arrow. When the slide par 85 moves in the direction of arrow C' or D', the light shielding piece 86 simultaneously moves in the direction of arrow C' or D'; Two photointerrupters 89α are located within the movement area of 86.

89b are arranged at appropriate intervals and in parallel to the moving direction of the light shielding piece 86.

The operating state of the shift detection means 84 described above is as follows. That is, when the recording medium 11 shifts in the direction of the arrow C, its edge 11C comes into contact with the contact piece 87α, and then the edge 11C presses the contact piece 87α, thereby moving the slider 85 in the direction of arrow C' force. Make it move. On this occasion,
Simultaneously with the movement of the slider 85 in the direction of arrow C', the light shielding piece 86 also moves in the direction of arrow C', but when the light shielding piece 86 reaches the position where it blocks the optical path of the photointerrupter 89α, at that point the light shielding piece 86 of the photointerrupter 89α A change occurs in the output signal.

That is, the shift of the recording medium 11 in the C direction is detected as a change in the output signal of the photointerrupter 89α.

On the other hand, the shift of the recording medium 11 in the D direction is detected as a change in the output signal of the photointerrupter 89h in the same manner as described above.

FIG. 25 is a diagram showing a fourth embodiment of the deviation detecting means based on the first idea, and in this figure, the deviation detecting means 90 has the following configuration.

In front of the curvature region of the recording body 11 corresponding to the roller 12 (to the left in the figure), there is a rotating arm extending in the axial direction of the roller 12 and having a length slightly longer than the width of the recording body 11. 91
is provided. This rotating arm 91 is rotatably supported by a fulcrum pin 92 at its center. Contact pieces 93α and 93b are attached to both ends of this rotating arm 91 so as to protrude rearward (to the right in the figure), and these contact pieces 93α and 93h are attached to both ends of the rotating arm 91 so that the recording medium 11 is rotated in the direction of arrow C or When moving in the direction of the arrow, the recording body 1
The length is long enough to come into contact with the end edge 11c or lid of 1.

In addition, in front of both ends of the rotating arm 91 (left side in the figure),
Photo interrupters 94α and 94b are arranged, respectively.These photo interrupters 94α.

94h has the same configuration as the photointerrupter 78 shown in FIG. Note that both ends of the rotating arm 91 are provided with light shielding pieces 91.
α, 91b are formed, and these light shielding pieces 91α, 9
The thickness of 1b is also smaller than the optical path interval of photointerrupters 94α and 94h. Therefore, when the rotary arm 91 rotates appropriately, the light shielding piece 91 (Z or 91h) can block the above-mentioned optical path in the same manner as in the case shown in FIG.

The operating state of the shift detection means 90 described above is as follows. That is, when the recording medium 11 shifts in the direction of arrow C, its edge 11C comes into contact with the contact piece 93α, and then the edge 11C presses the contact piece 93α, thereby moving the rotary arm 91 clockwise in the figure. Make it rotate. the result,
The rotating arm 91 reaches the state shown by the dashed line in the figure. The rotary arm 91, which has reached the state indicated by the dashed line in the figure, blocks the optical path of the photointerrupter 94α with its tip light shielding piece 91α. The photointerrupter 94α whose optical path is thus interrupted produces a change in its output signal at that point. That is, the shift of the recording medium 11 in the C direction causes the photointerrupter 9 to
It is detected as a change in the output signal of 4α.

On the other hand, the shift of the recording medium 11 in the D direction is detected as a change in the output signal of the photointerrupter 94h in the same manner as described above.

In each of the above embodiments, a combination of a photointerrupter and a light-shielding piece is used as a detection element, but the combination is not limited to this, and a combination of a microswitch and a contactor or a combination of a reed switch and a magnet is used. It is also possible to use conventionally known sensing elements, such as combinations.

The above is a description of the presence detection means based on the first idea, and next, the presence detection means based on the second idea will be explained. This second idea is based on the reflection type optical sensor placed oppositely near the edge of the recording medium, and the reflective type optical sensor placed oppositely near the edge of the recording medium, and This is intended to detect the deviation of the recording medium using a detection pattern that is movable into the detection area of the optical sensor and has a light reflectance different from that of the recording body.

FIG. 26 shows the first approach detection means based on the second idea above.
An example is shown. In the figure, belt roller 12
．． Detection patterns 95α having appropriate widths are formed on both ends of the endless belt-shaped recording medium 11 supported by the arrows 13 and driven in the direction of the arrow.

These detection patterns 95α and 95b are made of a material having a light reflectance different from that of the recording medium 11. A reflective optical sensor 96α is located in a flat area (linear area) of the recording medium 11, that is, in an area other than the area where the recording medium 11 is wound around the rollers 13 and 12, and at a position above both edges of the recording medium 11. 96b is placed.

FIG. 27 is a front view of FIG. 26, and clearly shows the positional relationship between the reflective optical sensors 96α and 96b.

The endless belt-shaped recording medium 11 in the figure is being driven normally, and therefore the recording body 11 is in a state where it does not shift in the direction perpendicular to the driving direction (direction C or direction D in the figure). Then, in this state,
The reflective optical sensors 96α and 96h are arranged above both edges of the recording medium 11 inside the detection patterns 95α and 95b, respectively, and in this case, the recording medium 11 is present in the detection areas of the sensors 96α and 96h. ing. therefore,
Sensor 96α.

96h produces an output signal corresponding to the light reflectance of the recording medium 11. In addition, in FIGS. 26 and 27,
For the sake of explanation, devices arranged around the recording medium 11 shown in FIG. 2 are omitted.

In the above configuration, the recording medium 11 is driven in the direction of the arrow. At this time, if a shift phenomenon occurs in the recording medium 11 in the C direction, the detection pattern 95h also moves in the C direction at the same time. After the detection pattern 95h moves a suitable distance, it reaches the detection area of the reflective optical sensor 96b, and at this point the output signal of the sensor 96b begins to change. After all, the light reflectance of the detection pattern 955 is the same as that of the recording medium 11.
This is because the light reflectance is different from that of . That is, the shift of the recording medium 2 in the C direction is detected as a change in the output signal of the reflective optical sensor 95b.

On the other hand, the shift of the recording medium 11 in the D direction is detected as a change in the output signal of the reflective optical sensor 96α in the same manner as described above.

FIG. 28 shows the belt-shaped recording body 1 in the above-mentioned drift detection means.
1 is a time chart showing the change in the output signal of the reflective optical sensor 96α or 96h due to the shift of the recording body 11. In this case, (C) is a time chart when the recording body 11 is shifted in the direction C, and (d) is a time chart when the recording body 11 is shifted in the direction C. This shows the case where the vehicle moves towards the direction of the vehicle.

In the figure (C), the recording medium 11 starts shifting in the C direction from mM (t = o) to the detection area of the detection pattern 95b and the sensor 96h (t = 'I) 1, when the sensor Both the recording body 1 is in the detection area of 96α and 96h.
1 exists, the output signal we of the sensor 96α and the output signal Wf of the sensor 96h both indicate an H level of 1-. After 11 hours, the recording medium 11 exists in the detection area of the sensor 962, and the detection pattern 95A exists in the detection area of the sensor 96h, so that we indicates the H level and the Wf FiL level. in this case,
The above H level and L level are determined by the light reflectance of the recording body 11 and the light reflectance of the detection pattern 95h, respectively.For example, the light reflectance of the recording body 11 is higher than the light reflectance of the detection pattern 95h. When it is large, the H level becomes a high level and the L level becomes a low level.

Next, from the moment Ct=0 when the recording medium 11 begins to shift in the D direction in figure d1 until the time when the detection pattern 95α reaches the detection area of the sensor 96α (1=t2), the 100 output signal The fact that We l Wf are both at H level is the same as in the case of FIG. After 62 hours, the detection pattern 95α is in the detection area of the sensor 96a, and the detection pattern 95α is in the detection area of the sensor 96a.
Since the recording medium 11 exists in the detection area of 6h, we indicates the L level and Wf indicates the H level.

FIG. 29 is a diagram showing a second embodiment of the shift detection means based on the second idea, in which the recording medium 11 supported by the roller 12
A detection pattern 97 is provided only on one edge thereof, and this detection pattern 97 has a light reflectance different from that of the recording medium 11, as in the first embodiment. In the figure, the recording medium 11 is being driven normally, so that the recording medium 11 is not displaced in a direction perpendicular to the driving direction, that is, in the C direction or D direction in the figure. In this state, detection pattern 9
A reflective optical sensor 98α is arranged at a position facing the detection pattern 97, and a recording body 11 located inside the detection pattern 97 is arranged.
A reflective optical sensor 98h is arranged above the end of the recording medium 11 in a direction perpendicular to the driving direction of the recording medium 11 and in the same line as the sensor 98α. In this case, the detection pattern 97 exists in the detection area of the sensor 98d, and the recording medium 11 exists in the detection area of the sensor 98h. Therefore, the sensor 98α produces an output signal corresponding to the light reflectance of the detection pattern 97, and the sensor 98h produces an output signal corresponding to the light reflectance of the recording medium 11.
.

In the above configuration, when the recording medium 11 is driven and a shift phenomenon occurs in the recording medium 11 in the C direction, the detection pattern 97 also moves in the C direction at the same time.

When the detection pattern 97 moves an appropriate distance, the detection pattern 97 reaches the detection area of the reflective optical sensor 986. Therefore, at this point, the sensor 98b
The output signal starts to change. In this case sensor 98α
Regarding, since the detection pattern 97 is always present in the detection area, no change occurs in the output signal of the sensor 98α. That is, the shift of the recording medium 11 in the C direction is detected as a change in the output signal of the reflective sensor 98b.

On the other hand, when a shift phenomenon occurs in the recording medium 11 in the D direction, the detection pattern 97 also moves in the D direction at the same time.When the detection pattern 97 moves an appropriate distance, the detection area of the reflective optical sensor 98α is The recording body 11 has arrived. Therefore, at this point, the output signal of the sensor 98α begins to change. In this case, since the recording medium 11 is always present in the detection area of the sensor 98h, no change occurs in the output signal of the sensor 98b. That is, the deviation of the recording medium 11 in the D direction is detected by the reflective sensor 98α.
is detected as a change in the output signal.

FIG. 30 shows a reflection type optical sensor 98α or 98 due to the deviation of the recording medium 11 in the second embodiment of the above-mentioned deviation detection means.
It is a time chart showing changes in the output signal of h, and (C
) The figure shows the case where the recording body 11 moves toward the C direction, and the figure (d) shows the case where the recording body 11 moves toward the D direction.

(C) In the figure, the detection pattern 97 starts from the moment when the recording medium 11 starts to shift in the C direction (t=0).
Until reaching the detection area of 8h (t=t3), the detection pattern 97 exists in the detection area of the sensor 98α, and the recording medium 11 exists in the detection area of the sensor 98b.
The output signal We' of the sensor 98α is at L level;
The output signal Wf' of 8h indicates H level.

After 63 hours, the detection pattern 97 will exist in the detection areas of both sensors 98α and 98h, so the We
' and Wf' both indicate L level.

The above H level or L level is the same as described above.

Next, in the figure (d), from the moment when the recording body 11 starts to shift in the D direction (t=0), the recording body 11 starts moving toward the sensor 98.
Until reaching the detection area of α (t-t4), the detection pattern 97 exists in the detection area of the sensor 98α, and the recording medium 11 exists in the detection area of the sensor 98b, so w
e' indicates L level, and Wf' indicates H level.

After 64 hours, since the recording medium 11 will be present in the detection areas of both sensors 98a and 98b, both we' and Wf' will often show an H level.

FIG. 31 is a diagram showing a third embodiment of the shift detection means based on the second idea, in which the support plate 26 and the top plate 2 are
A portion of the surface of the recording medium 8 near the roller 13 is configured as a detection pattern 99 having an appropriate interval, and this detection pattern 99 extends in a direction perpendicular to the driving direction of the recording medium 11. Note that this detection pattern 99 has a light reflectance different from that of the recording medium 11, as in the above-described embodiment. A reflective optical sensor 372 is arranged above the detection pattern 99 and facing the edge of the recording medium 11 .

As the recording medium 11 shifts in the direction D in FIG. 31, the detection pattern 99 on the top plate 28 gradually becomes exposed. When the 99 exposed detection patterns reach the detection range of the sensor 372, the output signal of the sensor 372 changes at that point, and the shift of the recording medium 11 is detected.

The above is a description of the deviation detection means, and next, the deviation control means will be explained.

FIG. 26 is also a diagram for explaining the operating principle of the shift control means. In the figure, the recording body 11 is a belt roller 1
2 and 13, and is driven in the direction of arrow A. One of these two rollers, the drive roller 13, has its rotating shaft 38 fixedly disposed as described above, and the other roller 12 passes approximately at right angles through the center of its axis and the axis of the rollers 12 and 13. Arrows 1. J. It is arranged so that it can be rotated, that is, tilted as appropriate. In this state, the roller 12
When the ends of both shafts of the rotor 2 are tilted in the direction of arrow 1, the recording body 11 shifts in the direction of arrow C. On the other hand, when the ends of both shafts of low month 2 are tilted in the direction of arrow J, the recording body 11 shifts in the direction of arrow C. Causes paralysis. This phenomenon is remarkable when the recording medium 11 is made of a material with low elasticity, such as polyester terephthalate.

Hereinafter, an embodiment of the shift control means based on the above principle will be described. In the following description, members that are the same as those already described are designated by the same reference numerals.

FIG. 32 shows one example of the shift control means, and the configuration thereof will be described in detail below.

One shaft end 121 of the roller 12 that supports the recording medium 11?
is supported by a notch 62α of a bracket 62 fixed to a side plate 67 of the main unit (see FIG. 4) with a screw 100, while the other roller shaft end 12h is supported by a control arm having a generally L-shape. It is supported by a notch 102 of a control piece 101α formed at one end of the control piece 101.

At its bent portion, the control arm 101 is attached to the side plate 60. of the main device by screws 103. (See FIG. 4) is rotatably attached to a fulcrum pin 104 provided in the. At one end of the control arm 101 other than the control piece 101a, a solenoid 105 is provided on the outside and a tension spring 106 is provided on the inside.
is located, the rod 10 of the solenoid 105
5α and one end of the spring 106 are connected to one end of the arm 101. When this solenoid 105 is energized, it acts to pull back the rod 105a toward the solenoid body. Therefore, in that case, the control piece 101α moves in the direction of arrow C in the figure, and at the same time the roller 12 also moves. It tilts in the C direction using the shaft end 12C as a fulcrum.

On the other hand, when the solenoid 105 is in a non-energized state, the control piece 101α moves in the direction of arrow P by the action of the spring 106, and at the same time, the roller 12 also tilts in the P direction using the shaft end 12C as a fulcrum.

When the recording medium 11 is driven in the direction of the arrow A under the above configuration, if the solenoid 105 is in a de-energized state, the roller 12 is moved in the direction of the arrow A in advance by the action of the spring 106.
tilted in the direction. Therefore, in that case, the recording body 11
has a tendency to move in the direction of the arrow, that is, to move toward the D direction, according to the above-mentioned principle. If the recording body 11 is D
If the direction exceeds the allowable limit, solenoid 10
By exciting the roller 5, the roller 12 is tilted in the direction of arrow C. This tilting stops the recording body 11 from shifting in the direction indicated by the arrow, and then the recording body 11 starts moving in the C direction. As a result, the deviation of the recording medium 11 in the D direction is corrected.

If the operation of the solenoid 105 causes the recording medium 11 to shift in the C direction by more than the allowable amount, the displacement of the recording medium 11 in the C direction is corrected by demagnetizing the solenoid 105. .

In the above example, the tilting of the rollers performed to control deviation is not greater than necessary. Therefore, although not shown in FIG.
It is preferable that a stopper be provided at an appropriate position on the movement path of the control arm 01 to prevent the control arm from moving more than a necessary amount.

In the deviation control means shown in FIG. 32, the driven roller 12 is provided so as to be tiltable with one end thereof as a fulcrum, and the other end is moved up and down to correct belt deviation.
The belt deviation may be corrected by changing the relative distance between both shaft ends of the drive roller 13 and both shaft ends of the drive roller 13.

As already explained, the recording body 11 has a spring 27 (fifth
(see Figure 6). Spring forces F'L and FR (second
6) are set to be, for example, FL) FR, the recording medium 11 is given a habit of moving in the direction of the arrow. On the other hand, the control arm is locked to the shaft end of the driven roller 12 to which the spring force FL is applied (see reference numeral 12b in FIG. 32). , by swinging the control arm, the tension applied to both sides of the recording medium 11 is changed so that PL ) FR. As a result, the recording medium 11
is displaced in the direction of arrow C. This displacement of the recording body 11 in the direction of arrow C is determined by the detection pattern 95 of the sensor 96α.
It is stopped when α is detected.

It goes without saying that control arms may be engaged with both shaft ends of the driven roller 12, and the roller may be tilted vertically or horizontally in response to a shift detection signal from the shift detector F).

In addition, in the above example, the drive means for the control arm is as follows:
Although a combination of a solenoid and a tension spring is used, the combination is not limited to this, and by receiving the required amount of rotation from the motor using an electromagnetic clutch, and transmitting that amount of rotation via a cam or gear, etc. A method of driving the control arm may also be used.

The above is an explanation of the shift detection means and the shift control means.
In reality, it is effective to use both as a combination. An example of this aspect will be shown and explained below.

FIG. 33 is a block diagram for driving the deviation control means based on the signal from the deviation detection means. In the figure, the recording medium deviation detection signal issued from the deviation detection means 107 is sent to the determination circuit 108, and The direction to be controlled and the timing of the control are determined. Once the direction and timing to be controlled are thus determined, the information is sent to the control signal generation circuit 109. Control signal generation circuit 10
At step 9, a control signal is generated to drive or stop a driving means, such as a solenoid, in the drift control means 110 placed at a later stage based on the information on the control direction and timing, and the control signal is transmitted to the drift control means 110. sent to.

By the way, the means for controlling the belt deviation is the driven roller 1.
2. On the other hand, a transfer charger 19 is provided near the lower side of the driven roller 12. That is, the area below the driven roller 12 is a transfer area where the toner image is transferred onto the recording paper.

Therefore, if belt deviation control is performed while a transfer operation is being performed, the movement of the recording body and recording paper in a certain direction is disturbed, causing problems such as black streaks and blurred transfer. Therefore, the belt approach control needs to be performed when no transfer operation is being performed, in other words, when the transfer charger 19 is not operating.

In FIGS. 88 and 89, shift detection (R) and (L) are provided to detect the shift of the recording medium at both edges thereof, and shift control is performed using 5QL (R) that tilts both ends of the driven roller 12.
.

A circuit diagram and a time chart are shown when using SQL (L).

In FIG. 89, the detection filler (reference numeral 77 in FIG. 20)
The belt deviation detection signal detected in (see) is ANDed with the inverted signal of the main motor control signal and transfer charger control signal output from the control circuit.
A solenoid 5QL (R, L) (for example, see reference numeral 105 in FIG. 32) is driven by a driver. Further, to prevent both solenoids from operating at the same time due to noise or the like, the inverted signal of one output signal is used as the gate signal of the other. As can be seen from FIG. 88, the solenoid is activated only when the main motor is driving and the transfer charger is not operating, that is, offset control is being performed. . Therefore, since the shift control is performed when no transfer operation is being performed, there is no adverse effect on the image.

Further, when the main motor is stopped, driving of the solenoid is stopped, so unnecessary power consumption is suppressed.

As described above, the blade that restricts the movement of the endless belt-like recording medium does not act on the side line portion of the endless belt-like recording medium, so that the recording medium is not deformed.

Furthermore, the apparatus is configured to detect the deviation of the belt-shaped recording medium, and based on the detected deviation, correct the deviation of the recording medium using a control means attached to the roller. Therefore, high precision is not required in the construction of the belt-shaped recording body and the rollers.

Furthermore, since the shift detection means, shift control means, etc. themselves have a simple structure, the recording apparatus does not become complicated, large, or expensive.

The printer of the present invention employs a magnetic brush development method that uses a magnetic developer to visualize an electrostatic latent image.

The magnetic brush development method uses a non-magnetic cylindrical stub,
It is composed of a developing roller consisting of a magnet disposed inside the sleeve, and by moving the two relative to each other, a magnetic brush is formed on the surface of the sleeve, and the electrostatic latent image is rubbed by the magnetic brush to form a visible image. This is a method of Among dry developing methods, this magnetic brush developing method is most commonly used in many recording devices such as copying machines, printers, plotters, and facsimile machines because of its ease of practical application.

In such a magnetic brush development method, in order to perform development without uneven development, the toner concentration must be uniform and the height of the magnetic brush must be approximately constant. In order to make the toner concentration uniform, it is necessary to perform sufficient stirring, mainly in the case of a two-component developer. On the other hand, in order to keep the height of the magnetic brush constant, a doctor blade is required that is attached a predetermined distance from the sleeve surface, thereby regulating the developer drawn up by the sleeve to a constant height. I have to.

However, it is already known that in the magnetic brush development method using a -component developer, the distance between the sleeve and the doctor blade is o1~l, Q mm, and in the magnetic brush development method using a two-component developer, In the grab development method, the interval is 1.
0-3. Q mm. As described above, if the distance between the sleeve and the doctor blade is very small, white streaks may occur on the copied image.

The present inventors investigated why this white streak phenomenon occurs. According to the results, it was found that the part of the doctor that corresponded to the white streaks was clogged with paper powder, dust, metal powder, etc.

Normally, when the collected developer is returned to the developing device for reuse in the cleaning section, paper dust, metal powder, etc. are mixed in the developer, and paper dust is scattered inside the machine. , dust, metal powder, etc. may be mixed into the developer. Therefore, as described above, if the distance between the sleeve and the doctor blade is too small, the space between them will become clogged, and the developer will not be able to pass therethrough sufficiently, resulting in a decrease in the amount of developer in some areas.

As a result, the height of the magnetic brush becomes low, and either it does not come into contact with the electrostatic latent image surface in that area, or even if it does, the contact pressure becomes extremely small and almost no development occurs, resulting in so-called white streaks. Understood. Of course, a similar phenomenon occurs when the developer aggregates.

The occurrence of the cholera phenomenon was remarkable in the -component development method in which the distance between the doctor blade and the sleeve was narrow.

The printer of the present invention includes a developing device that implements a developing method that prevents the occurrence of the white streak phenomenon.

In this developing method, the magnetic field distribution of the magnetic field generating means is set between the position where the magnetic developer is supplied to the sleeve and the developing position so that the developer does not exist parallel to the axis of the sleeve when the sleeve is at rest. It develops an electrostatic latent image. In addition, in this developing method, a magnetic field generating means is provided between the position where the thickness of the developer layer on the sleeve is regulated by the regulating member and the developing position, so that the developer does not exist parallel to the axis of the sleeve when the sleeve is at rest. The electrostatic latent image is developed by setting the magnetic field distribution.

When the rotation of the sleeve is stopped, by changing the shape of the magnet disposed inside the sleeve, the shape of the magnetic brush formed on the sleeve can be changed by the magnetic force of the magnet.

For example, the magnetic poles of the magnets fixedly installed in the sleeve are such that the polarity of adjacent magnets is usually opposite to each other, but the magnetic developer that has been attached to the sleeve surface is transferred to the recording medium. In order to create a cloud state of developer, the polarity of the two magnets was set to be the same, albeit partially.

In order to achieve the object of the present invention, for example, among the magnets disposed inside the sleeve as a magnetic field generating means, adjacent magnets between the developer supply position and the development position are made to have the same polarity. will be held. However, the purpose of blowing the developer on the sleeve outward is not to create a cloud state; on the contrary, it is not preferable to blow the developer outward because it may cause the problem of developer scattering. In the present invention, magnetic poles of the same polarity are arranged between the developer supply position and the development position or between the position for regulating the layer thickness of the developer on the sleeve and the development position without causing the developer to fly, and the sleeve The magnetic field distribution was set so as to create a region where no developer exists parallel to the axis of the sleeve when the sleeve is at rest.

In FIG. 34, the developing device 16 includes a non-magnetic cylindrical developing sleeve 34 that rotates counterclockwise, and the sleeve 3.
Magnets 111 and 112 as magnetic field generating means provided in 4
．． It consists of 113.114.115.116.

The sleeve 34 is disposed at the opening of a developer container 33 that stores developer. As the developer, a one-component developer consisting only of magnetic toner is used. A side wall for developer discharge of the developer container 33: 33hK has a developer regulating member 117 attached thereto. This developer regulating member 1
17 is in a positional relationship facing the magnet 116. Further, the magnet 111 is a main developing pole, and is a concave magnet with four parts cut in the center. This magnet 111 is located closer to the sleeve 3 than the closest position between the recording medium 11 and the sleeve 34.
It is arranged so as to face slightly upstream when viewed in the rotational direction of 4. The other magnets are arranged so that north and south poles alternate.

When the sleeve 34 rotates, developer is carried out from the developer container 33 in the direction of rotation of the sleeve 34. However, since the developer regulating member 117 is disposed at the outlet, excess developer on the sleeve is removed and a developer layer of a constant thickness is formed. This results in a magnetic brush of constant height being formed on the sleeve.

By the way, as mentioned above, the main developing pole 111 has a central part of 4
Parts have been cut. For example, looking at the magnetic force on the surface of the sleeve 34, the portion corresponding to both ends of the magnet is approximately 1
There are 200 Gauss, but the part corresponding to the center part is about 800 Gauss.
It is Gauss. When such a magnet is used, when the rotation of the sleeve 34 is stopped, no developer is present in the area corresponding to the central portion of the magnet. As shown in FIG. 35, a portion 118 where no developer is present is formed parallel to the axial direction of the IJf printer 34. Moreover, the portion 118 is within the range R shown in FIG.
You have to let it be within you. That is, it must exist between the part where the developer is supplied to the sleeve and the developing section. As can be seen from FIG. 35, a portion 118 where no developer exists is slightly upstream of the developing section indicated by the symbol T in the figure (as seen in the direction of rotation of the sleeve).
It's starting to come.

Now, if foreign matter gets stuck between the developer regulating member 117 and the sleeve 34, the developer will not be supplied to this area as described above. Therefore, the third
As shown in FIG. 5, an unsupplied portion 119 is formed on the sleeve 34 after the developer is supplied. However, before the developer reaches the developing section T, there is a portion 4 where no developer is present.
118, there is a portion where no developer exists in the axial direction, and the supply shortage caused by the developer regulating member 117 is almost eliminated. This means that the developer is
This is because it can be easily moved to the most stable position. As a result, as shown in the figure, the insufficient supply of developer to the extent that it can be seen that there is a significant shortage of developer across the entire width of the developing section T is resolved.

When such a developing device was used to visualize the electrostatic latent image on the recording medium 11 and make a copy, the occurrence of white streaks due to insufficient supply of developer was almost eliminated, and even if there was an effect, it was The severity was minor.

In the magnetic brush developing device used in the above example, when the magnet 111 as the main developing pole was replaced with two magnets 111A and IIIB of the same polarity arranged close to each other as shown in FIG. 36, the same result was obtained. sleeve 3
On the surface of the sleeve 34 when the rotation of No. 4 is stopped, the above-mentioned No. 2
No developer was present in the area corresponding to the intermediate portion between the two magnets 111A and IIIB.

That part is surrounded by a broken line in the figure. Even when developing using such a developing device, the same results as in the first example were obtained.

Furthermore, in the above example, the magnet group within the sleeve 34 was rotated approximately 60° clockwise and fixed as shown in FIG. In this way, 111 adjacent magnets of the same polarity and 1
11B faces the developer regulating member 117. It has been found that the same results as in the above example can be obtained as long as the portion where no developer is present on the sleeve 34 is between the developing section and the developer regulating member.

In the example shown in FIG. 38, an electrostatic latent image is developed by a developing device in which two portions where developer is most likely to exist are formed between the developer regulating member 117 and the developing section. For this reason, magnets 111A, IIIB, and IC of the same polarity were arranged at equal intervals between the developer regulating member 117 and the developing section. In this case as well, even if a partial toner supply shortage occurs at the developer regulating member 117, the developer is carried through the two areas where no developer exists, so the toner supply shortage occurs. The toner was supplied to the areas where the toner was removed, and no phenomena such as white streaks occurred.

The following example is basically the same as the example shown in Figure 36, but the magnetic field generating means is a rod-shaped magnet, and the N and S poles are magnetized on the surface as shown in Figure 39. Cylindrical magnet 120
It was used. This cylindrical magnet 120 also has manufacturing advantages, such as being able to be assembled at any desired magnetization position and with a highly accurate spacing between the sleeve 34 and the magnet surface.

When a magnetic toner with an average particle size of 10 μm to 13 μm was used as a developer and the linear speed of the recording medium 11 was 7 Qmm/sec and the linear speed of the non-magnetic sleeve was 210 mm/sec, no white streaks were generated and the results were good. A developed image was obtained.

Note that, when the linear velocity of the recording body is vp and the linear velocity of the sleeve is VS, good results were obtained in the range of VS/Vp = 1.5 to 4.0. However, VS is 50-300 m
m/sec, preferably 150~3QQ mm/S
I got good results when I set it to ec.

By the way, in the above-mentioned embodiments, all have been described as having one developer regulating member, but in those having multiple developer regulating members, the developer regulating member closest to the developing section is At least one portion where no developer is present may be magnetically formed between the developing portion and the developing portion.

The characteristic of the one-component development method is that the volume occupancy of the magnetic powder in the magnetic toner is extremely small, so the amount of magnetization per toner is small, and the magnet in the developing sleeve It is difficult to form a coarse and long magnetic brush like a magnetic brush. Even if a thick toner layer is formed, unevenness is likely to occur in the toner layer, leading to density unevenness on the image. Therefore, in the case of a -component developer, it is necessary to form a thin and uniform magnetic brush on the developing sleeve.

However, since the layer is thin, once the developer layer is subjected to development, there is a large difference in the thickness of the developer layer between the portion corresponding to the image area and the portion corresponding to the non-image area. Even if this was left as is and new developer was supplied, there was a difference in characteristics between the developer remaining on the surface and the newly supplied developer, or a uniform layer was not formed again. This causes uneven image density and afterimages.

Furthermore, as the amount of triboelectric charge increases, the electrostatic attraction force of the residual toner to the developing sleeve increases, making it increasingly difficult for the residual toner to separate from the developing sleeve.

In order to improve the above-mentioned drawbacks, conventional methods have been proposed in which the toner remaining on the developing sleeve is removed using a scraper, or a hole is provided in the scraper plate to return the scraped toner onto the developing sleeve. There is.

However, when using a scraper, since the scraper is in contact with the developing sleeve, there is a problem in that fine adjustment of the scraper installation is required, and there is also the problem that the developing sleeve may be damaged by the scraper. Also,
Since the scraper presses the toner, it tends to promote toner aggregation, and furthermore, if the scraper is wavy, there is a problem that the toner cannot be removed smoothly.

On the other hand, when a scraper with holes is used, the scraper with holes is brought into contact with the developing sleeve, and the toner removed from the developing sleeve is returned to the developing sleeve through the holes, thereby stirring the toner.

However, since the blade is similarly structured so that it comes into contact with the developing sleeve, if the blade waves and separates from the developing sleeve, it will no longer be able to perform its function, and there is a possibility that the blade or developing sleeve may be damaged or that the toner may aggregate. be. Furthermore, when making many copies of the same document, even if the toner is removed from the toner image sleeve, the toner is supplied onto the developing sleeve again before it is sufficiently mixed with the new developer in the toner hopper, causing the image to deteriorate as described above. Density unevenness and afterimages may occur.

This developer improves the above-mentioned conventional drawbacks, and can remove the toner remaining on the developing sleeve without contacting the developing sleeve, preventing damage to the developing sleeve and toner aggregation, and ensuring a good performance at all times. It is also equipped with a developing device that can produce stable images.

In FIGS. 2 and 34, inside the developer container 33,
A first stirring member 190 provided on the stirring shaft 189 and a second stirring member 191 provided in parallel to and not in contact with the developing sleeve 34 are provided.

The second stirring member 191 is made of a shaft-shaped magnetic material, and has a screw-shaped mountain-shaped protrusion 192 formed therein, as shown in FIG.

Further, a mechanism 193 for reciprocating the second stirring member 191 and reciprocating the second stirring member 191 relative to the developing sleeve 34 is connected to the second stirring member 191 and the stirring shaft 18.
It is located between 9. The mechanism 193, as shown in FIG.
and a fork-shaped lever 196 that is slidably fitted around the bottle 195 and whose base is fixed to the end of the second stirring member 191. Therefore, when the stirring shaft 189 rotates in a certain direction, the lever 196 changes the rotational movement into a reciprocating rotational movement of the second stirring member 191, and the second stirring member 19
1 performs equal angle forward and reverse rotation.

In the above-mentioned developing device, the magnetic lines of force of the second agitating member 191 are concentrated in the narrow gap between the protrusion 192 and the developing sleeve 34, and a portion of the toner is held between the developing sleeve 34 and the toner in that narrow gap. , a portion of the toner coming later is moved slightly laterally as shown by arrow d in FIG. 58, resulting in lateral agitation. In addition, the second stirring member 19
1 is rotating, so the toner moves in the direction of arrow e,
The toner held between the aforementioned developing sleeve 34 also
The remaining toner on the developing sleeve 34 is gradually replaced with other toner, and the remaining toner on the developing sleeve 34 is removed and stirred. Note that when the second stirring member 191 rotates only in one direction, the toner is transferred to the container 3.
3, which has a negative effect on development, and also causes pressure on the toner due to rotation, which promotes toner aggregation. However, since the second stirring member 191 rotates back and forth, the same toner is always mixed. Since the toner is not held between the second stirring member 191 and the developing sleeve 34 and is rotated at a low speed of a few rpm or less, toner aggregation does not occur, and the toner on the developing sleeve 34 is removed and stirred.

Further, the shape of the second stirring member 191 does not necessarily have to be screw-like as shown in FIG.
Like the stirring member 191A, a structure may be adopted in which a plurality of circular flanges 192A are provided around the shaft portion 191Aα.

In this case, as shown by the axial arrow f, it is necessary to reciprocate the position relative to the developing sleeve 34 at a low speed. However, it is not necessary to rotate the axis 91Aα. Furthermore, the shape of the second agitating member may be any shape as long as it is provided with protrusions arranged parallel to the axis of the developing sleeve 34 and moves back and forth in the axial direction.
It is not necessary to rotate as in the embodiment shown in FIGS. 59 and 59. In other words, it is sufficient that the toner is retained between the mountain-shaped protrusion and the developing sleeve to achieve the same function as in the embodiment described above.

As explained above, according to the present device, the second stirring member is provided close to the developing sleeve in a non-contact state, and a mechanism is provided for reciprocating the stirring member relative to the developing sleeve. Therefore, residual toner can be removed and agitated without coming into contact with the developing sleeve, preventing damage to the developing sleeve and toner aggregation, and providing good and stable images at all times.

For the first time, the recording medium/developing unit 5 is as described above.
Although the developing device unit 31 supports the recording body unit 23 and the two units are integrated, it is necessary to pull out the unit from the printer body periodically or irregularly. For example, replenishing developer and replacing the endless belt-like recording medium are routine maintenance operations, although the frequency may vary. The developer replenishment interval is much shorter and more frequent than the regular recording medium exchange interval.

When replacing the recording medium, the operation cannot be performed unless the unit is completely pulled out from the main body, but when replenishing the developer, the lid 33α of the container 33
It is enough to pull out the unit far enough to open it. On the other hand, it is better to avoid exposing the recording medium 11 to the outside of the apparatus as much as possible. This is because indoor illumination light tends to deteriorate the photosensitive characteristics and cause scratches and dust to adhere.

Therefore, in the present invention, the recording medium/developing unit 5
A configuration is adopted in which the amount of withdrawal can be selected depending on the content of the maintenance operation.

In FIG. 40, there is a hole 56 in the approximate center of the guide plate 56.
α is formed, and a locking piece 121α of the stopper 121 faces this hole. The stopper 121 is
As shown in FIG. 4, it is fixed to a support shaft 122 supported between side plates 60 and 67. Further, a spring 123 is hung on one end of the soba 121, and the locking piece 1 of this
21α is given a rocking behavior in the direction of protruding from the hole 56α.

At one end of the support shaft 122, one end 1 of the operating arm 124 is attached.
24a is fixed. An operating knob 125 is fixed to the other end of this arm, and this operating knob 125 is
As shown in FIG. 1, it is made to protrude to the outside of the main body. On the other hand, an engagement hole 39α is formed in the bottom plate 39 of the unit.

As shown in FIG. 40, when the recording medium/developing unit 5 is installed in the main body of the apparatus,
The stopper 121 is in contact with the lower surface of the bottom plate 39. When the unit 5 is pulled out in the direction of the arrow from this position, the locking piece 121α slides against the lower surface of the bottom plate 39, and as shown in FIG. , the withdrawal operation will be regulated and you will not be able to withdraw any more. This position shown in FIG. 41 is a position where the developer container 33 is pulled out of the machine and its lid 33α can be opened and closed, and is a developer replenishment position where developer is replenished into the container. In this case, the recording unit 23 is located inside the body. Therefore, the recording medium 11 is not exposed to indoor lighting,
Deterioration of its characteristics can be prevented.

When replacing the recording medium 11, after pulling out the unit 5 to the position shown in FIG.
The unit may be pulled out of the machine after the first locking piece 121α is retracted from the engagement hole 39α. When installing the unit into the main body after replacing the recording medium, the stopper 121 has a tapered portion that is connected to the tip edge 39h of the bottom plate 39 (
(See Fig. 12), it rotates by being pushed, and the mounting operation can be performed without resistance.

Although FIG. 40 shows an example in which the stopper 121 is engaged with and disengaged from the bottom plate 39 of the unit 5, the stopper may act on the side plate 36. This example is shown in FIG. 42, in which a stopper 127 supported by a support shaft 126 is provided near the side plate 36. This tension bar 127 is urged by a spring 128, and causes the locking piece 127α to abut against the side plate 127. One end 127h of the strip (127) abuts one end of the operation slider 129.

This slider 129 connects the guide hole 129α with the fixing pin 13.
0 and can be slid freely. On the other hand, an engagement hole 36b (see FIG. 43) is formed in the side plate 36.

When the unit 5 is pulled out in the direction of the arrow (Fig. 42) and the locking piece 127a is fitted into the engagement hole 36h, this position (
Drawing out of the unit 5 is restricted in FIG. 43). The position of the unit at this time is the developer replenishment position shown in FIG. Stopper 12 that locks the unit at the position
7 simultaneously pushes the operating slider 129 to project the operating knob 129h outside the machine. If you want to pull the unit completely out of the machine, push in the operating knob 129b shown in FIG.
If you move it out of the way and release the stopped state at the intermediate position, it will be possible to pull it out.

When an endless belt-like recording medium is used, phenomena such as sagging and waving occur in the recording medium between the belt rollers. For this reason, the position of each device provided on the recording layer must be carefully considered.

As for the developing device, by integrating the developing device unit and the recording body unit, it is possible to maintain a constant developing gap. This has already been stated.

An exposure device is required to be more precise in its positional relationship relative to the recording medium than the developing device.

The best way to keep the position of the recording medium and exposure device constant is to wrap the belt around the roller only in the so-called curvature area E (second
(See Figure 2). However, in this case, the scanning line of the scanning beam is parallel to the axis of the belt roller,
The preconditions must be met. If the belt roller has a small diameter and the belt rollers are not parallel, uneven exposure will occur in the axial direction of the roller, in other words, in the width direction of the recording medium.

Further, it is also necessary to provide the charging charger at a position where its relative position with respect to the recording medium does not change as much as possible. Particularly in the case of a scorotron type charger, it is necessary that all the grid wires have the same distance from the recording medium.

The printer of the present invention satisfies the above requirements when setting the exposure position and the charging position.

In FIG. 22, the recording medium 11 is divided into four regions depending on flatness, speed characteristics, etc. Of these four areas, the areas where the recording surface has little positional variation with respect to other constituent units are the tension side line area G and the drive side curvature area El.

Further, the region where the feeding speed of the recording medium is stable is the driving side curvature region El and the tension side line region Gl near the driving side curvature region El. In the slack side line area G, fluctuations in the position and feed speed are likely to occur due to phenomena such as waviness of the recording surface, and in the driven side curvature area E, fluctuations in the feed speed are likely to occur.

Considering the characteristics of each region of the endless belt-like recording medium 11 described above, the steps of charging, exposure, and development, which are important for image formation, are performed in the linear region G on the side where the endless belt-like recording medium 11 is stretched.
To be more specific, during the movement from 1 to the drive side curvature area E1, the exposure position is a straight line area where there is little variation in the recording surface and little speed variation, just before the recording body 11 contacts the drive roller 13. The linear region Gl is selected, and the developing device is set to the recording medium 11 with the least variation in development gap and speed variation.
and the drive roller 13 are arranged in a curvature region E1 in contact with the drive roller 13,
Further, it is suitable for the above-mentioned purpose to provide the charger 14 in the linear region of the recording medium and on the tension side Gl where the fluctuation of the surface of the recording medium is small.

That is, as shown in FIG. 2, the charger 14 exposes the straight line area of the recording medium 11 on the stretch side, and the exposure device 15 exposes the straight line area immediately before the recording medium changes from the straight line area to the curvature area. Each position is set to emit light.

The charger 14 is a scorotron type charger.

The fog light device 15 uses a gas laser such as 1e-JJe or a semiconductor laser as a light source, modulates and deflects the light source beam, and scans a minute beam spot on the recording medium while changing the light intensity ( However, the printer of the present invention is not limited to such an exposure format.

In this way, by setting the incident position of the exposure device in a flat area (straight line area) near the part where the endless belt-shaped recording medium 11 changes from a flat surface to a curved surface, the parallelism of the scanning beam to the width direction of the recording medium can be improved. Adjustment accuracy becomes easier.

Next, a paper feeding device that feeds recording paper toward a recording medium will be described.

One of the devices for feeding recording paper includes a tray that stacks the recording papers on a movable bottom plate, and when the bottom plate is pushed up by a push-up member biased by a spring, the above-mentioned Some recording sheets are configured such that the uppermost one of the recording sheets on the bottom plate is pressed against a paper feed roller and fed by the paper feed roller, and the tray is provided so as to protrude from the outside of the device. In some cases, the tray is provided with a top cover member that can be opened and closed to prevent the recording paper from getting dirty.

When replenishing recording paper in the recording paper feeding device as described above, first push down the push-up member using the operation lever, open the top cover member, and replenish the recording paper into the tray in this state. Then, the upper lid member must be closed and the push-up member must be released from being pressed down using the operating lever. Furthermore, in the case of a so-called cassette system in which the tray is removable from the device, in addition to the operations described above, it is necessary to remove the cassette from the device and reinsert it. Replenishment work becomes troublesome.

According to the present invention, when the top cover member of the recording paper tray is opened, the bottom plate is automatically pushed down, making it possible to replenish the tray with recording paper, and when the top cover member is still closed, the bottom plate is automatically pushed down. The bottom plate is automatically pushed up by the action of the spring, and the recording paper can be fed. Therefore, in this recording paper feeding device, recording paper can be replenished by simply opening and closing the top cover member. Further, in this recording paper feeding device, there is no need to provide a push-up member on the main body of the device, and the structure of the printer can be simplified.

By the way, in the above-mentioned recording paper feeding device, in addition to the sensor that detects the presence or absence of recording paper on the bottom plate, the top cover member is closed, and the bottom plate is pressed against the paper feeding roller to normally feed the paper. A sensor is required to detect whether or not work is possible.

Also, the bottom plate rises and presses the recording paper against the paper feed roller.
By the rotation of this paper feed roller, multiple sheets of recording paper are sent out, and by using the difference in the coefficient of friction with the friction pad,
In a paper feeding device that feeds only one sheet of recording paper out of the tray, when replenishing recording paper, a situation occurs in which the supplied paper is not set correctly. The leading edges of multiple sheets of recording paper are sandwiched between the paper feed roller and the friction pad. When the bottom plate is lowered in this state, the recording paper sandwiched between the two will not follow the bottom plate and descend, but will remain pinched at its leading edge, and a new recording paper will be placed on top of it. When placed, the printer of the present invention includes a sensor that detects the presence or absence of recording paper, and a bottom plate that moves the recording paper to the paper feed roller when the top cover is closed. It is equipped with a detection device configured so that one sensor can serve as a sensor for detecting whether or not the pressed paper is in a state where normal paper feeding operation can be performed.

It is also equipped with a paper reset mechanism that ensures that when the bottom plate is pressed down when replenishing recording paper, the recording paper that was held between the paper feed roller and friction pad is returned to the tray. There is.

In FIG. 2, reference numeral 130 generally indicates a paper feeding device. The recording paper stored in the paper feeding device is divided into a paper feeding roller 17 and a friction pad 131 from the highest to the highest.
The sheets are fed one by one by the cooperative action of the guide plate 132.
The paper is guided by and sent to a pair of transport rollers 18. The presence or absence of recording paper in the paper feeder 130 is detected by a paper end sensor 133.

The paper feeder 130 has a box-shaped tray 3 with an open top. The rear part of the bottom of the tray 3 is a fixed bottom plate 134.
The front part is composed of a movable bottom plate 135. The movable bottom plate 135 is substantially pivoted to the tray 3 at its rear end 136, and is tiltable up and down about the pivot point. The movable bottom plate 135 is urged upward in the figure by the spring force of a compression coil spring 137.

The tray 3 is provided with an upper lid 4 whose one end is pivotally supported by a pivot 138 to open and close the upper part of the tray 3.

As shown in FIG. 44, the upper lid 4 has bearing pieces 139 bent on both sides of its front end.

The pivot 138 is fixed to a side plate (not shown) of the tray 3. The bearing piece 139 has rollers 141 and a support shaft 1.
42, and a locking bottle 143 is fixedly planted. The rollers 141 face the upper surface of both side edges of the movable bottom plate 135.

A swing arm 145 is swingably attached to the front end of the side plate of the recording paper tray by a pivot 144. One end of the flick 7 arm is connected to the support 146.
A friction pad 131 made of rubber or rubber-like material is supported. Friction pad 1
31 is brought into pressure contact with the paper feed roller 17 by the elasticity of a tension coil spring 147 whose one end is locked to the arm 145. The friction arms 145 are pivotally attached to both side plates of the tray, and the friction pad 131 is supported approximately at the center of the connecting portions 148.

The other end of the spring 147 is secured to a bottle 149 fixed to a side plate (not shown) of the tray. An interlocking lever 148 is swingably supported on this pin. One end 148α of the interlocking lever 148 is bent and faces one end 145α of the arm 145. The other end 148h of the interlocking lever 148 extends below the support shaft 142 of the roller 141 described above. The support shaft 142 extends to a position where it can engage with the other end 148b of the lever.

At the front end of the recording paper tray 3, a support shaft 151 is supported by a pair of arms 150 (only one shown) extending from both side plates of the recording paper tray 3. A swing lever 152 is fixed to one end of the support shaft 151, as also shown in FIG. Both ends of a connecting rod 154 are locked between a pin 153 of the same type at the free end of the swing lever 152 and the locking pin 143. A paper reset lever 155 is fixed to the support shaft 151. Paper reset lever 15
5, as shown in FIG. 46, a pair of paper feed rollers 17 are provided so as to be positioned between them. Further, the free end of the paper reset lever 155 is located above the upper edge of the front plate 156 of the tray (FIG. 44).

(See Figure 45). The front plate 156 is formed with a notch 156a into which the lever 155 is swung, and a notch 156b into which the friction pad 131 enters.

As shown in FIG. 44, when the top cover 4 is closed, K
In this case, the friction pad 131 comes into pressure contact with the paper feed roller 17, and the paper reset lever 155 separates from the front plate 156.
The compression coil spring 137 pushes up the movable bottom plate 135 and presses the plate against the lower open surface of the paper feed roller 17. In this case, when recording papers are stacked on the bottom plate 135, the uppermost recording paper is pressed against the lower surface of the paper feed roller 17.

To explain the operation when setting the recording paper, as shown in FIG.
A roller 141 provided at 39 abuts against the movable bottom plate 135 and pushes the bottom plate 135 down against the elasticity of the spring 137 as shown in FIG. Thereafter, a bundle of recording paper is inserted between the open top lid 4 and the movable bottom plate 135, and its leading edge is brought into contact with the front plate 156. Next, when the top cover 4 is closed as shown in FIG. 44, the bottom plate 135 rises due to the elasticity of the spring 137, and presses the uppermost one of the stacked recording sheets against the surface of the paper feed roller 17.

By the way, recording paper is replenished when a paper end sensor 133 (described later) detects a paper end and notifies the operator of this, and when additional recording paper is added even if there is still paper in the tray. There are cases. In the latter case, the paper feed roller 17 and the friction pad 131
Since the leading edges of several sheets of recording paper are held between the two, it is necessary to drop these recording sheets into the tray.

When further recording paper is placed on top of the recording paper, as shown in FIG. 44, when the closed top cover 4 is opened as shown in FIG. 45, the connecting rod 154 connected thereto moves. , the paper reset lever 155 is swung clockwise via the swing lever 152 and the support shaft 151, and the support shaft 14
2 engages with one end 148b of the interlocking lever 148 to swing the lever clockwise, and the other end 148a of the lever
to swing the friction arm 145 counterclockwise. That is, when the top cover 4 is opened, the friction pad 131 moves the paper feed roller 1 as shown in FIG.
7, the leading edge of the recording paper that was held between them is released. At the same time, the paper reset lever 155 swings so that its leading edge collides with the leading edge of the released recording paper, pushing the patterned paper back into the tray. Therefore, when replenishing new paper while there is still recording paper in the tray, there is no paper between the paper feed roller 17 and the friction pad 131, and the paper is placed on the movable bottom plate 135 that has been pushed down. This means that the paper is placed in an orderly manner, and paper can be replenished on top of the paper.

In the example shown in FIG. 44, the paper reset lever is directly linked to the upper lid 4, but it may be linked to the movable bottom plate 135 that swings in conjunction with the upper lid 4.

This example will be explained based on FIGS. 47 to 49. A paper reset lever 1587>f is fixed to the support shaft 151. A spring 159 is applied to this lever 158, giving it a swinging habit that moves the lever away from the front plate 156. Further, the engaging piece 158α of the lever 158 is projected into the tray from a hole 156C formed in the front plate, and is located at a position where it can engage with the front edge of the movable bottom plate 135.

In Fig. 47, when the top cover 4 (see Fig. 44) is opened,
The movable bottom plate 135 is lowered as shown in FIG. At the same time, the friction band 131 moves away from the position of paper feeding = r 017, and the leading edge 2 of the recording paper 24 that was being held between the two
Release 4α. When the movable bottom plate 35 is lowered, its front edge engages with the engagement piece 158a, causing the paper reset lever 158 to swing as shown in FIG. When this lever 158 swings, the upper paper that has passed over the upper edge of the front plate 156 has its front edge pushed and moved by the lever 158, and is pushed back onto the lower recording paper that is lowered together with the movable bottom plate. It will be done. When the top cover is closed after supplying new recording paper, the movable bottom plate 135 rises and the paper reset lever 158 swings back to the position shown in FIG. 47 by the elasticity of the spring 159.

In FIG. 44, a bracket 160 is fixedly arranged above the movable bottom plate 135 in the drawing. This bracket 160 rotatably supports a shaft portion 162 of a filler 161, as clearly shown in FIGS. 50 to 52. The filler 161 is aligned with the opening 135a formed in the rotary bottom plate 135 at one end 163 of the filler, and when there is even one recording paper 24 on the movable bottom plate 135, the fifth
As shown by the solid line in FIG. 1, it rides on the recording paper and maintains the rotational position as shown in the diagram, while it falls onto the movable bottom plate 135, and in FIG. It is positioned at the rotational position shown by the line. A detection plate 16 is attached to the end of the shaft portion 162 of the filler 161.
4 is fixedly attached at its center portion 165 with a screw 166. [Detection plate] 64 has a shirt flap piece 167 at its tip, and this shirt flap piece 167 is a photoelectric switch 168 in which a light emitting element and a light receiving element are arranged facing each other.
The light emitting element selectively enters the opposing gap 169 of the light emitting element and the light receiving element to selectively block the optical axis between the light emitting element and the light receiving element. The detection plate 164 detects that when the filler 161 is in the position shown by the solid line in FIG. When the shirt shirt piece 167 is in the position shown in FIG.
It is installed so that it protrudes from 69. The photoelectric switch 168 outputs different signals to a control device (not shown) depending on whether the optical axis is blocked or not. Note that the control device may be configured to determine that the recording paper feeding device is in a state in which recording work can be performed only when the optical axis is blocked. Further, an interlocking plate 170 is fixed to the shaft portion 162 of the filler 161 at its hub portion 171 with screws 172. In addition, the tray 3 has a filler 173 on the shaft 17 at its side plate.
It is pivotably supported at 4. This filler 173 selectively engages with the lower bottom surface of the top cover 4 at one filler end 175, and when the top cover 4 is in the normal closed position, a spring 176 is attached as shown by the solid line in FIG. When the upper cover 4 is opened by more than a predetermined angle from the closed position, the spring force is applied, as shown in FIG. 17
6 is rotated to a position where it abuts against the cyst collar pin 177. The filler 173 selectively engages the interlocking plate 170 at its retaining end 178;
When the top cover 4 is in the closed position, one end of the filler 163. as shown in FIG. Detection plate 164 and interlocking plate 17
0 is allowed to move freely between the position shown in solid lines in the figure and the position shown in phantom lines in the figure, whereas when the top cover 4 is opened from the closed position, the spring 176 When rotated counterclockwise in the figure, the interlocking plate 170
The detection plate 164 is driven to a position where the shutter piece 167 of the detection plate 164 is pulled out of the opposing gap 169.

Therefore, the shirt flap piece 167 of the detection plate 164 can be positioned within the opposing gap 169 of the photoelectric switch 1680, as shown by the solid line in FIG.
This occurs only when at least one sheet of recording paper 24 is present on the top cover 3 and the top cover 4 is in the normal closed position.

When there is no recording paper 24 on the movable bottom plate 1351, the filler 1 is removed as shown by the imaginary line in FIG.
When one end 163 of the filler 61 falls into the opening 135α, the detection plate 164 rotates counterclockwise in the figure, and the seven pieces 167 are pulled out from the opposing gap 169 downward in the figure. Further, when the upper lid 4 is not in the normal closed position, the filler 17 is closed as shown in FIG.
3 and the interlocking plate 170, the detection plate 164 is rotated clockwise in the figure, and is pulled out from the opposing gap 169 upward in the figure. At this time, the filler 163 is lifted and separated from the movable bottom plate 135, making it easier to replenish the recording paper. .

From the above description, it will be understood that according to the present invention, the presence or absence of recording paper on the bottom plate and the open/closed state of the top cover can be detected with a single photoelectric switch.

The paper feed roller 17 is provided above the front plate 156 of the recording paper tray 4, and is located approximately at the widthwise center of the tray (see FIGS. 2 and 4). As is clear from FIG. 4, the paper feed rollers 17 are arranged so as to alternate with the circumferential surface of the upper roller 181Z of the transport roller pair 18. The upper roller 18a and the lower roller 18h are pressed against each other. The driving of each of these rollers will be described later.

As shown in FIG.
is installed. This registration sensor 179 detects the recording paper fed out from the tray 4 and held between the pair of conveyance rollers 18, and when the recording paper is detected, the pair of conveyance rollers 18, the paper feed roller 17 The details will be described later.

Incidentally, a recording medium/developing device unit is arranged above the paper feeding device 130, and a cleaning device 22 is arranged further above it. The cleaning device 22 collects and removes the developer remaining on the surface of the recording medium 11 after transfer. Therefore, when replacing the recording medium or replenishing the developer, when the unit 5 is pulled out in whole or in part from the main body, the developer collected by the cleaning device 22 may be damaged by vibrations or impact on the paper feeding device, especially the conveyance roller. 18. Paper feed roller 17. There is a risk that it may fall onto the friction pad 131. When the developer adheres to each of the above rollers.

The coefficient of friction on the surface of the rollers and pads changes, making it impossible to carry out normal recording paper feeding operations. Additionally, unnecessary developer adheres to the recording paper, resulting in dirty copies. Further, as the recording medium moves, a powder image formed on the surface of the recording medium may become floating toner and stain the recording paper or rollers.

By the way, after the recording paper is sent out from the tray, it is brought into close contact with the recording medium, and the recording paper needs to be fed in a predetermined direction while maintaining its posture.

A mechanism for protecting the paper feeder from contamination will be described below. Second
In the figure, a recording paper guide cover 180 is arranged below the recording medium/developing device unit 5 by 1Ml. This guide cover 180 covers a position and range that protects the recording paper and its conveyance path from developer falling towards them. As shown in FIG. 53, the guide cup;
81 and 182 are engaged with positioning pins 183 and 184, and are disposed between the side plates 60 and 67. Positioning bin 1
83 and 184 are similar to the guide plates 56 and 56, as only one of them is shown in FIGS. 8 and 54.

The guide cover 180 consists of a portion 180α, the positioning pieces 181 and 182, and a guide portion 180b formed by bending the tip edge thereof. This guide cover 180 is removably set on the positioning pins 183 and 184 by utilizing the space formed after the recording medium/developing unit 5 is taken out from the main body of the apparatus. Positioning bins 183 and 184 and positioning pieces 181
, 182, the guide cover 180
The position in the front/back/left/right direction and downward direction is restricted. 54th
The figure shows the roller pair 18 and the recording paper 24 to show that the guide cover covers a wider area than the conveyance roller pair 18 and the recording paper 24.

After setting the guide cover 180, when the recording medium/developing unit 5 is attached to the main body, the receiver is attached to the bottom plate 39 of the section 35.
This restricts the upward position of the cover.

As shown in FIG. 2, when the guide cover 180 is attached to the main body of the apparatus, the guide portion 180h cooperates with a guide plate 185 fixed to the main body to guide the recording paper path 18.
6. This guide cover 180 prevents the recording medium from being removed even if all or part of the unit 5 is pulled out from the main body of the apparatus during operations such as replacing the recording medium or replenishing the developer.
1 and a cleaning device 22;
The recording paper and its path are isolated from each other to prevent contamination caused by falling developer or floating developer.

Further, the guide portion 180h of the guide cover 180 constitutes a recording paper path and functions to maintain the posture of the recording paper being conveyed to the transfer area. The following effects can be mentioned as effects of not fixing such a cover to the main body of the apparatus. If the friction coefficient of the paper feed roller 17 decreases, normal paper feeding will no longer be possible, so it is necessary to periodically clean the paper feed roller 17.

During such cleaning and maintenance work, after pulling out the unit 5, the guide cover 180 is attached to the positioning pins 183 and 18.
4, maintenance work from the opening of the device can be performed extremely easily.

In the above explanation, the guide plate 185 constituting the recording paper path 186 was provided in the main body of the apparatus, but as shown in FIG.
The guide plate 185A may be provided so as to be substantially integrated with the guide portion 180b.

The guide cover 180 shown in FIGS. 56 and 57 has a leaf spring 187 or a foam 18 on the upper surface of the cover part 180α.
The fixing device used in the apparatus of the present invention is of a roller fixing type.

Generally, this type of roller fixing type fixing device is provided with a separating claw to prevent the recording paper from being wrapped around the fixing roller after fixing. However, in many conventional separation claws, the tip of the separation claw is always in contact with the fixing roller. When the separating claw is in constant contact with the fixing roller, the toner adhering to the fixing roller is gradually scraped off and adhered to the tip contact portion of the separating claw. For this reason,
If the toner is used for a long period of time, the tip of the separating claw will be lifted off the fixing roller due to the adhered toner.

As a result, the separation claw cannot separate the recording paper normally, and
This recording paper gets caught in the separation claw and causes a jam. Also, because the tip of the separation claw is in constant contact, it may cause scratches on the Teflon coated on the surface of the fixing roller.
Fixation cannot be performed well in this area, and white streaks or the like occur in the fixed image, resulting in a decrease in image quality.

Therefore, an electromagnetic drive device such as a plunger is used, and the electromagnetic drive device is driven by an electric signal only when separating the recording paper to contact and rotate the separating claw, and keep it separated except when separating the recording paper. It has been known. However, since a drive device is required to move the separating claws toward and away from each other, this method, including its control system, is structurally and electrically complex, requires space, and is expensive.

The fixing device for a printer according to the present invention can ensure that the separating claw is separated from the fixing roller without using any special parts or devices, and can easily prevent the adverse effects caused by the separating claw being in constant contact with the fixing roller.

This fixing device makes the circumferential speed of the paper ejection roller faster than the circumferential speed of the fixing roller, and uses the tension of the recording paper in the pinched conveyance state by both rollers as a driving source to separate the recording paper through a protrusion that protrudes into the recording paper conveyance path. By rotating the claws away from each other, it is possible to obtain the necessary contact and separation state of the separating claws with respect to the fixing roller with a simple structure.

In FIG. 61, a fixing roller 197 and a pressure roller 198 are provided in opposing contact with each other in the fixing device to form a pair of fixing rollers. The fixing method using this pair of fixing rollers may be either a heating method or a pressure method, but for example, in the case of a heating method, the pressure necessary for fixing is applied between both rollers only during the fixing operation when the recording paper 24 passes. A one-turn clutch, a sliding friction mechanism, etc. are provided as appropriate.

Further, with respect to the fixing roller 197, there is a separating claw 201 which is rotatable about a shaft 199 and is biased counterclockwise by a spring 200, and whose tip 201α contacts the surface of the fixing roller 197. A cleaning mechanism 202 for wiping off adhered toner is provided. A guide plate 203 is provided on the paper ejection side of the pair of fixing rollers.
A pair of paper ejection rollers 25 consisting of rollers 204 and 205 is provided via the rollers 204 and 205. Therefore, a recording paper conveyance path 206 as shown by a dashed line in FIG. 61 is formed. A paper ejection sensor 272 is disposed in this conveyance path 206 and detects recording paper passing through the path. In the illustrated case, the sensor 272 shows only the filler, and its tip 272a is located on the passage.

Therefore, the circumferential speed of the fixing roller 197 is set to be slower than the circumferential speed of the paper ejection roller pair 25. In addition, the separation claw 20
A protruding portion 201h that protrudes into the recording paper conveyance path 206 with its tip 201 (Z) in contact with the fixing roller 197 is provided on a part of the recording paper 1 on the opposite side from the tip 201a.

In such a configuration, the recording paper 24 having an unfixed toner image is sent between the fixing roller 197e and the pressure roller 198 and fixed thereon. The tip of this recording paper 24 is a spring 20
Separation claw 20 in contact with fixing roller 197 by 0
The sheet is separated from the fixing roller 197 by the leading end 201a of the sheet 1, and moves toward the pair of sheet discharge rollers 25 along the guide plate 203. When the leading edge of the recording paper 24 reaches between the paper ejection roller pair 25, the recording paper 24 is pushed by both the fixing roller 197/pressure roller 198 and the paper ejection roller pair 25, as shown in FIG. This results in a situation where the product is transported in a pinched state. At this time, since the circumferential speed of the paper ejection roller pair 25 side is set faster than the circumferential speed of the fixing roller 197/pressure roller 198 side, the recording paper 24 located in the recording paper conveyance path 206 is ejected. It is pulled by the pair of rollers 25 and becomes in tension. Note that since the clamping force between the fixing roller 197 and the pressure roller 198 is stronger, there is no problem in the fixing operation. On the other hand, a protrusion 201b protrudes into this recording paper conveyance path 206, and the protrusion 201h is pushed by the tension of the recording paper 24, and as shown in FIG. 62, the separation claw 201i <It rotates clockwise and its tip 201α becomes the fixing roller 197
will be separated from. For this purpose, a spring 200 is used to bring the separation claw 201 into contact with the fixing roller 191.
The biasing force is set smaller than this tension. Then, when the rear end of the recording paper 24 is removed from the fixing roller 197 and the pressure roller 198, the tension is applied and the separation claw 201 is returned to its original position by the spring 200, and the leading edge 2
01α returns to contact with the fixing roller 197.

Therefore, when the recording paper 24 is being held and conveyed by the fixing roller 197, the pressure roller 198, and the paper ejection roller pair 25, it is possible to ensure that the separating claw 201 is separated from the fixing roller 197, and at other times. By bringing the leading end 201α into contact with the fixing roller 197, the original separating action of the recording paper 24 can be performed and a standby state can be obtained. In order to perform this operation, the tension of the recording paper 24, which is stretched with a circumferential speed difference between the fixing roller 197 and the paper ejection roller pair 25, is used as a driving source, so that the separating claw 201 approaches and separates. No special drive source or members are required for operation, making it simple and reducing costs. Further, in order to use the tension of the stretched recording paper 24 as a driving source for displacing the separation claw 201, a difference in circumferential speed is provided between the fixing roller 197 and the paper ejection roller pair 25. As a result, it is possible to prevent paper jams by conveying the paper in a stretched state. Therefore, according to this example, the defects such as the occurrence of scratches on the fixing roller 197 caused by the constant contact of the separating claw 201 with the fixing roller 2197, and the uncertainty of separation due to toner adhesion to the tip 201a can be easily eliminated, and the fixing roller 2197 can be easily fixed. The lifespan of the roller 197 and the separation claw 201 can be extended to improve the separation performance, and a highly reliable fixing device without jamming can be achieved.

Regarding the reliability of the fixing device, it is also necessary to keep the circumferential surface of the fixing roller clean.

In FIGS. 61 and 63, a heater 207 inside the fixing roller 197 is located at the upper non-sheet passing portion of the fixing roller 197.
The thermistor TH that controls the temperature is in contact with it. The cleaning mechanism 202 is arranged on the entry side of the fixing roller 197. Reference numeral 209 denotes a pad made of heat-resistant felt, one end of which is sandwiched between a bracket 210 and an aluminum holder 211 and fixed with a screw 212, and the other end is inserted along the circumferential surface of the fixing roller 197. Being pressed.

A cushion 213 is made of a soft heat-resistant material such as foamed silicone rubber, and is used to perform the cleaning action of the band 209 more softly and to prevent the fixing roller 197 from being scratched.

Both ends of the bracket 210, as shown in FIG.
It is fixed to the bent piece 214a of the frame 214 with a stepped screw 215. This position is 1° from the center of the fixing roller 197.
only pointing downwards. The height of the stepped screw 215 is set to be greater than the thickness of the platen 210. Therefore, the difference between the height of this step and the plate thickness of the bracket 210 is determined by the elastic force of the band 209 and the shoejoy 2130, and is selected to be an appropriate value.

A magnetic member 216 is fixed to the upper part of the bracket 210 by a fixing bracket 217, and is close to the fixing roller 197.

Next, the effect will be explained. Bracken) 210 is pressed downward by 2 from the center of the fixing roller 197 by the stepped screw 2, so the bent portion 214α of the frame 214
The pressing force of the roller 209, which tilts outward with the lower end of the fixing roller 197 as a fulcrum, is strongest at the lower part 75 and gradually becomes weaker as it goes upward.

Therefore, the toner adhering to the fixing roller 197 is
A portion is removed above 09, and the remaining force is completely cleaned at the bottom. That is, efficient cleaning is performed over the entire surface of the throat 209, and the amount of toner adhesion and accumulation above the throat 209 is reduced. Even if toner accumulates above the radar 209, the aggregated toner 218 is attracted to the magnetic body 216 and does not sink into the pressure contact surface of the band 209.

As shown in FIG. 61, it can be opened and closed by a hinge 219 attached to a bracket 225 of the main body.

Further, the upper cover 220 of the fixing device 20 is attached to the stay 222 by a hinge 221 so as to be openable and closable.

A bracket 22 for supporting the shaft 199 is provided on the cover.
3 and a holder 224 that supports the paper ejection roller 205 are fixed. When the upper cover 220 is opened, the recording paper conveyance path 206 within the fixing device is opened, making it easy to remove jammed paper and inspect the interior.

As shown in FIG. 1, the printer of the present invention is provided with a recording paper tray 10 on the back side of the printer body. Therefore,
The operator must reach out to retrieve the printed recording paper. Therefore, it is convenient to configure the paper ejecting means so that the operator can pick up the recording paper while sitting on the chair.

In FIG. 61, after removing the cover 9 from the hinge 219, the hinge 219 is attached to the hinge 219 as shown in FIG.
Replaced with 26. The hinge 226 has a paper ejection unit 227
Lower ends 228α of a pair of side plates 228 (only one is shown) are fixed. Bent portion 228b of side plate 228.

A unit cover 229 is screwed to 228C via stopper plates 230 and 231. One side plate 228
As shown in FIGS. 62 and 65, the Boo IJ2
32 and gear 233 are supported coaxially and rotatably. The gear 233 meshes with a gear 235 that is integrated with the shaft 234 of the paper ejection roller 206. The roller 206 is
The drive system will be explained later. The side plates 228, 228 (only one shown) include
A paper discharge roller 236 is rotatably supported by its shaft 237. A pulley 238 is fixed to one end of the shaft 237, and a belt 239 is wound between the pulley 238 and the pulley 232.

A paper discharge port 240 is formed in the unit cover 229, and the paper discharge roller 236 is located inside the paper discharge port 240. The paper discharge roller 236 is made of an elastic material such as foamed polyurethane rubber, and its upper peripheral surface is pressed against the press plate 241. The recording paper is conveyed while being held between the rotating paper discharge roller 236 and the presser plate 241, but the structure may be such that the two are separated from each other. This example is shown in FIG. 66, in which the presser plate 241 has a pair of protrusions 241
is formed, and the presser plate and the paper discharge roller are not in contact with each other, but the peripheral surface of the roller and the protrusion are positioned so as to fit into each other when viewed from the axial direction.

Curved guide members 242 and 243 are provided between the pair of paper discharge rollers 25 and the paper discharge roller 236, and form a recording paper turn path 244. In FIG. 62, the recording paper is transported through the conveyance path 206. The paper is discharged from the paper discharge port 240 through the turn path 244 onto the upper cover of the printer main body in the direction indicated by the arrow. The recording paper discharged onto the top cover of the printer can be easily picked up by an operator who is sitting on a chair.

The paper ejection unit 227 is attached to the main body of the apparatus by a hinge 226 so as to be openable and closable, and the upper part of the fixing device can be opened by opening this, similar to the cover 9 shown in FIG. 61. By the way, the magnet 245 is attached to one end 228d of the side plate 228, and the hinge 22
When the receiver fixed to 1 is magnetically fixed to the plate 246, the meshing of the gears 233 and 235 is ensured.

The transfer charger 19 includes a discharge electrode 247 connected to a high-voltage power source (not shown) and a shield case 248 thereof. The transfer charger 19 is attached to the side plate 8 of the main body.
It can be opened (see Figure 1) and pulled out in the direction of the arrow.

The electrification charger 14 is of the scorotron type and consists of a discharge electrode 249 and a grid 250, each connected to a power source (not shown), and a shield case 251 for these. Like the transfer charger 19, this electrification charger 14 can also be attached to and detached from the main body of the apparatus in the same direction.

The charger 14 and the transfer charger 19 each radiate corona discharges of the same polarity toward the recording medium 11 and the back surface of the recording paper.

In the case of the example shown in FIG. 1, the static eliminator 21 uses an AC corona or a DC quality lamp 253 with a polarity opposite to that of the recording medium.
and a shield case 254.

In this example, the charger is placed to the left in order to eliminate static electricity not only from the recording medium but also from the recording paper, and in the figure of the shield case 254, the left side is located to prevent the recording paper from jamming. It's open. By arranging the static eliminator at the so-called curvature portion where the recording medium 11 is wound around the roller 12, the separability of the recording medium and the recording paper is improved in addition to the curvature separation.

Next, the configuration of the cleaning device 22 will be explained based on FIG. 2. The cleaning device is removable from the printer body in the same direction as each charger, and includes a casing 255 and cleaning rollers 256 . It mainly consists of a magnetic roller 2571 and a collection shaft 258. The cleaning roller 256 includes a non-magnetic sleeve 259 with short fibers planted on its surface, and three magnets h 260.2 in the illustrated example arranged inside the sleeve 259.
It consists of 61.262. The above non-magnetic sleeve 2
59 is rotated clockwise by a drive system that will be described later. For example, fibers with a length of about 0.3 to 1 mm, such as synthetic fibers such as nylon and rayon, natural fibers such as cotton and wool, and conductive fibers such as carbon and metal, are coated on the surface of a non-magnetic sleeve made of aluminum. Paste it to form a sleeve, and attach it to the surface of the recording medium at a distance of 0.2 to Q, 5.
The residual magnetic toner on the surface of the recording medium is removed by rotating the sleeve while maintaining an interval of about 1.0 mm, that is, bringing the fibers on the sleeve surface into contact with the surface of the recording medium at a distance of about 0.1 to Q, 5 nm. The residual magnetic toner on the recording medium is mechanically peeled off by the fibers on the sleeve surface, and
In this type of cleaning device, which is attracted to and held on the sleeve surface by the magnetic force of the magnet inside the sleeve and transported by the rotation of the sleeve, in order to perform good cleaning, the distance between the sleeve and the surface of the recording medium must be maintained at all times. need to be maintained constant.

In other words, uniform contact between the fibers on the sleeve surface and the recording medium surface is maintained. If this is not the case, the cleaning will be uneven, and the next recording will not be performed well due to toner remaining uncleaned or insufficiently cleaned.

For this reason, in the past, bearings with a diameter slightly larger than the sleeve diameter were provided at both ends of the sleeve, and these were brought into contact with the surface of the recording medium and rotated, thereby keeping the distance between the sleeve and the surface of the recording medium constant. It was being maintained. However, this method has drawbacks such as a complicated mechanism, high cost, and foreign matter such as toner adhering to the contact area between the bearing and the recording medium, which gradually reduces the accuracy of maintaining the gap.

The cleaning device 22 of this printer includes a cleaning roller capable of generating a magnetic field on the surface of a reservoir for removing magnetic toner remaining on the surface of a recording medium, and a magnetic body facing the cleaning roller with the recording medium interposed therebetween. and, by arranging at least one of the cleaning roller and the magnetic body so as to be substantially freely movable, the recording medium is held between the cleaning roller and the magnetic body by the magnetic force of the cleaning roller. It is characterized by As a result, the contact between the cleaning roller as a cleaning member and the surface of the recording medium becomes uniform, and not only good cleaning is possible, but also the structure is simple and manufacturing and assembly is easy.

On the other hand, the magnetic roller 257 has its surface in contact with the cleaning roller 256, and magnetically transfers the developer removed by the roller 256 from the surface of the recording medium. A blade 263 is in pressure contact with the circumferential surface of the magnetic roller 257 to scrape off the transferred developer. The scraped developer falls onto the collection shaft 258.

The collection shaft 258 has a spiral groove formed on its outer periphery or is made of a coil spring, and rotates in one direction to transport the developer in the axial direction. Collect into container.

The recording medium 11 is wound around a pair of belt rollers 12, 13, and these belt rollers form a support plate 26. The axis of the driven roller y112 may not be fixed in order to correct belt deviation, and the axis of the drive roller 13 may be fixed in order to adjust the exposure position or ground contact. Already mentioned.

By the way, the bearing 43 of the driven roller 12 and the groove 40 (
(see FIG. 6). In other words, in the recording unit 23 mounted inside the apparatus, the support plate 26 can swing slightly around the shaft 38 of the drive roller 13 as a fulcrum.

Therefore, as shown in FIG. 67, the top plate 2 of the support plate 26
8, a facing member 264 made of a magnetic material is provided on the lower surface of the cleaning roller 256, facing the entire axial direction of the cleaning roller 256.
is fixed. As the means for fixing, appropriate means such as adhesives, adhesive tapes, screws, etc. may be used. Therefore, the facing member 264 is substantially movably disposed, and is attracted by the magnet in the non-magnetic sleeve 259 and moves upward, passing through the recording medium 11 and the top plate 28 of the supporting member 26. and is attracted to the surface of the non-magnetic sleeve. In this case, even if the surface of the non-magnetic sleeve 2590 and the surface of the recording medium 11 are not parallel, the recording medium 11 will come into uniform contact with the surface of the sleeve 259, and the residual magnetic toner on the recording medium 11 will be unevenly removed. Clean evenly. The magnetic toner adhering to the surface of the non-magnetic sleeve 259 is
9, and is conveyed by the rotation of the magnetic roller 257.
and further scraped by the blade 263,
It is discharged to the outside of the IJ-ning device by the collection shaft 258. In this example, belt roller 12.1
3 and the rotation axis of the non-magnetic sleeve 259 are parallel, and the top plate 28 of the support member 26 and the non-magnetic sleeve 2
If the surface of support roller 12 is parallel to
．． It is not necessarily necessary to provide a clearance between the rotation shaft 13 and the support member 26 that supports it.

The above example is an example in which the recording medium 11 is lifted together with the recording medium unit, but in another example schematically shown in FIG. It is simply placed in the In such a configuration, only the opposing member 264 is lifted to bring the recording medium 11 into uniform contact with the surface of the cleaning roller 256. Therefore, there is no need to provide an extra clearance between the rotating shaft of the belt roller 12 and the support member 26, and a certain gap is provided between the opposing member 264 and the surface of the cleaning roller 256 so that the opposing member 264 can be lifted. Just set it up.

Such a configuration, as shown in FIG.
The top plate 28 of No. 6 can be modified to have an opening for the counter member 264, and the counter member 264 rests on the receiving plate 267 supported by the bins 265, 266 on the top plate 28. In this configuration, the facing member 2 is also
Only 64 is connected to the cleaning roller 25 along with the recording medium 11.
69 is adsorbed on the surface. When the opposing member 264 is fixed to the receiving plate 267, the receiving plate 267 and the pins 265, 266
If the fitting with the receiving plate 26 is made loose, the facing member 264 will be
Every 7 can be lifted.

In the case of such a type in which the opposing member 264 directly contacts the moving recording medium 11, the contact resistance is minimized to reduce the load, or conversely, the contact area with the non-magnetic sleeve 259 is reduced. In order to increase cleaning efficiency by increasing the size as much as possible, the surface of the opposing member 2640 on the side of the recording medium 11 can be changed into various shapes as shown in FIG. 70.

That is, the surface that contacts the recording medium 11 has rounded corners, a convex curved surface, or a concave curved surface.

The role of the facing member in this cleaning device is not only to bring the surface of the recording medium into uniform contact with the cleaning roller by being magnetically attracted to the cleaning roller facing it, but also to make it "conform". The objective is to effectively move the residual toner on the recording medium by the magnetic field formed there, thereby enhancing the cleaning effect. , it may be difficult to create an effective magnetic field that moves residual magnetic toner from the surface of the recording medium. Therefore, in the device described above, the opposing positions of the cleaning roller and the opposing member are relatively changed. Although either the cleaning roller or the opposing member may be moved, it is more convenient to adjust the position of the opposing member from the perspective of the power transmission system.

Various means can be used to adjust the position of the facing member, but after positioning, a long hole parallel to the moving direction of the recording medium 11 is formed in the facing member 264, and a screw passing through the long hole is inserted into the top plate 28. It may be fixed by tightening.

This device is characterized in that at least one of the cleaning roller and the opposing member is arranged to be substantially freely movable. As is clear from the above explanation, "substantially" means
Instead of disposing the cleaning roller or the opposing member itself so that it can move freely, it is possible to fix them to other members,
This includes cases where other members are movably arranged. In addition, "to be able to play" means so-called "play".
, with "gata" meaning "in a movable state". Since "at least one of the cleaning roller or the opposing member" is used, unlike the above embodiments, it is possible to move the cleaning roller or to move both of them.

By the way, as a means for bringing the recording medium 11 into contact with the cleaning roller 256, the following effects can be mentioned as effects of arranging the opposing member 264 made of a magnetic material on the back surface of the recording medium 11.

In order to improve the cleaning effect, the recording medium 11 and the cleaning roller 256 should be in sliding contact with each other.
What is necessary is to determine the mutual positional relationship. However, in the apparatus of the present invention, the recording medium 11 is provided as a unit so as to be movable in a direction perpendicular to the axial direction of the cleaning roller 256).

Therefore, if the recording medium and the cleaning roller are always kept in contact regardless of the pulled-out position of the unit, there is a risk that they will rub against each other and damage the surface of the recording medium when the unit is inserted or removed. In this regard, in this device, since the opposing member 264 that is attracted to the magnet 260 built into the cleaning roller 256 is arranged,
The risk of damage to the recording medium is minimized. That is, only when the recording medium/developing unit 5 is pushed to a predetermined position in the apparatus, the facing member 264 is attracted by the magnet 26o (see FIG. 67) and the recording medium 11 is moved to the cleaning roller 2.
56, the opposing member 26
4 is moved to a position where it is not affected by the influence of the magnet 260 or the magnetic force that brings the recording medium into contact with the circumferential surface of the roller 256, the recording medium 11 separates from the circumferential surface of the roller 256.

As a means for bringing the recording medium 11 into contact with the cleaning roller 256, a means to replace the opposing member 264 made of a magnetic material will be described next. This is an example in which the recording medium 11 is brought into contact with the cleaning roller 256 in the axial direction with a uniform blade.

In FIG. 71, a facing member 268 made of a flexible material and having approximately the same length as the sleeve 259 is fixed to the top plate 28 at a position facing the non-magnetic sleeve 259. The flexible material may be rubber, sponge, felt, brush bristles, etc., or a material wrapped or sealed with a jelly-like substance or liquid, and may just have flexibility. , those having elasticity are more preferable.

Since the flexible material only needs to be applied to at least the portion of the opposing member 268 that contacts the recording medium 11, the opposing member 268 can be constructed by pasting the flexible material onto a rigid material. However, even in such a case, the flexible material must have a thickness that allows it to sufficiently contract when pressed.

Since the top plate 28 originally supports and guides the upper side of the recording medium 11, the surface of the top plate 28 and the back surface of the recording medium 11 are in contact with or are very close to each other, and the surface of the cleaning roller 2560 and The surfaces of the recording body 11 are also in contact or in close proximity. By interposing the facing member 268 having a certain thickness between the cleaning roller 256 and the top plate 28 in such a positional relationship, the facing member 268 made of a flexible material receives pressure and at the same time, the sleeve surface The recording medium 11 is brought into uniform and soft contact with the sleeve surface. In addition to this, record body 11
The residual magnetic toner on the surface is evenly and uniformly cleaned.

In order to press the opposing member 268 against the cleaning roller 256 via the recording medium 11, a spring 269 can be used as shown in FIG. That is, a recess is provided in the top plate 28 at a position facing the cleaning row 2256, and the opposite member 268 is placed in the recess with the spring 269 facing down. As a result, the facing member 268 is pressed upward, and the recording medium 11 is brought into pressure contact with the cleaning roller 256. Of course, if the opposing member 268 is sufficiently thicker than the recess, the spring 269 will be unnecessary. One spring 269 may be provided approximately at the center of the top plate 28 in the depth direction, or one spring 269 may be provided at each end thereof. Opposing member 2
Since 68 is only supported by spring 269,
Because it can move in any direction, that is, it can be free to move,
Even if the cleaning roller 256 and the recording medium 11 are not parallel, the recording medium 11 always "follows" the surface K of the cleaning roller 256 and comes into uniform contact with it.

In this manner, in this apparatus, the upper surface of the opposing member 268 is always in contact with the back surface of the recording medium 11, so in order to reduce the contact resistance as much as possible and reduce the load,
Alternatively, in order to increase the contact area between the recording body 11 and the IJ-ning roller 256 as much as possible to enhance the cleaning effect, the top surface shape of the opposing member 268 can be changed in various ways as shown in FIG. 70. . That is,
The surface that contacts the recording medium 11 has rounded corners, a convex curved surface, or a concave curved surface.

Further, in each of the above embodiments, since the non-magnetic sleeve 259 containing a magnet therein is used as the cleaning member, as shown in FIG.
If a magnetic body or a magnet 270 of opposite polarity to the opposing magnet in the sleeve is attached below, this magnetic body or magnet 2
70 is attracted to the magnet in the sleeve, so the facing member can be brought into pressure contact with the cleaning roller via the recording medium without using any mechanical pressure contact means. A specific example of this is shown in FIGS. 74 and 75.

In FIG. 74, a cushioning material 271 made of the flexible material is provided on the surface facing the recording medium 11 of the facing member 264 having the configuration shown in FIG. 68, and the cushioning material 271 is brought into contact with the back surface of the recording medium. It is something that

In FIG. 75, in the example shown in FIG. 67, a cushion material 271 is provided on the top plate 28 facing the cleaning roller 256, and the cushion material 271 is brought into contact with the back surface of the recording medium.

As shown in FIGS. 74 and 75, the IE of the recording body 11
When the cushioning material is brought into contact with the surface K, the opposing member 264 attracted by the magnetic force of the cleaning roller 256 moves toward the recording medium 1.
1 is pressed against the cleaning roller 256, the pressure is uniform along the generatrix direction of the roller. In other words, since the recording medium 11 comes into uniform contact with the cleaning roller 256 in its width direction, the recording medium can be cleaned evenly and satisfactorily.

The drive system of this printer will be explained based on FIG. The rotary shaft of the motor 273 as a drive source is equipped with Goo I7274.
, 275 are integrally attached. Pulley 274
(2) An endless timing bell (which is rotated around pulleys 276, 277, 278 and tension pulley 279)
80 is wrapped around it. The above pulleys 276, 277
, 278 are rotatably attached to the side plate 67 (see FIGS. 4 and 8) at respective shafts 281, 282, and 283.

A gear 63 is fixed to the shaft 281 of the pulley 276, and meshes with a gear 64 that is substantially integral with the drive belt roller 13, as shown in FIGS. 8 and 13. A gear 66 of the developing sleeve 34 meshes with the gear 64 .

A gear 284 is fixed to the shaft 282 of the pulley 277, and this gear 284 is connected to the cleaning roller 25.
It meshes with a gear 286 fixed to a shaft 285 of No. 6.

A gear 287 is fixed to the shaft 283 of the pulley 278, and this gear 287 is connected to the shaft 283 of the fixing roller 197.
It meshes with a gear 289 fixed to 88.

A gear 290 that is integrated with the shaft 291 of the pressure roller 198 meshes with the gear 289 . Therefore, the rollers 197 and 198 rotate without slipping relative to each other. As shown in FIG. 62, a gear 235 is fixed to the shaft 234 of the paper discharge roller 206, and idle gears 292 and 293 are in mesh with each other between the gear 235 and the gear 289. It is provided. A one-way clutch 294 is provided between the gear 289 and the shaft 288, so that driving force is transmitted only from the gear 289 to the shaft 288. Therefore, when the drive system is stopped, the fixing roller 197 can freely rotate in the direction of conveyance of the paper.

Another pulley 275 of the motor 273 has a pulley 2
A timing belt 296 is wound between the timing belt 95 and the timing belt 95. As shown in FIG. 4, the pulley 295 is attached to the shaft 297 of the lower roller 18b of the pair of conveying rollers 18 via a conveying latch 299 consisting of an electromagnetic clutch.

When this conveying latch 299 is energized, the pulley 295 and the shaft 297 rotate integrally with each other. This state is defined as the clutch being turned on. A gear 298 is fixed to the shaft 297 of the lower roller 18b, and a gear 301 fixed to one end of the shaft 300 of the upper roller 18α meshes with this gear 298. As shown in FIG. 4, a gear 3 is attached to the other end of the shaft 300.
A gear 303 is fixed to this gear 302.
are engaged. The gear 303 connects the shaft 305 of the paper feed roller 17 via a paper feed clutch 304 consisting of an electromagnetic clutch.
is installed on. When the paper feed clutch 304 is energized, the rotation of the gear 303 is transmitted to the shaft 305 to rotate the paper feed roller 17 in the paper feeding direction. The paper feed roller 17 is connected to a shaft 305 via a one-way rotation clutch 306.
When the shaft 305 is not rotating, the roller can freely rotate.

As described above, the printer of the present invention uses one motor as the only driving source. The drive by the motor and the actions of various sensors and electromagnetic clutches will be described later.

In the present invention, recording is performed using an endless belt-like recording medium, and in this recording method, the joints (seams) of the recording medium
must be treated as a non-recording area (invalid recording area). Therefore, when recording, it is necessary to detect the recording start position or joint of the recording medium by some means and record while avoiding the joint. Furthermore, during recording, it is not a preferable method to take a long time to start recording due to the rotation of the recording medium, or to continue rotating the recording medium even after a predetermined recording has been completed.

The present invention implements a recording method that avoids the above problems.

FIG. 76 shows the sequence control unit of the printer of the present invention, in which CPU, ROM, RAM, '/ are the central processing unit, read-only memory, random access memory, and input/output board that constitute the microcombinator. . 2 is the main switch, 307 is the main relay,
308 is the main relay drive power supply, 309 is the AC drive system,
310 is a control system power supply, 311 is a power switch, 312 is a resistor, 313 is a transistor, 314 is a slit disk 315 fixed to the shaft 281 of the gear 63 that rotates the drive shaft of the recording medium 11, and a photointerrupter that detects the slit. A timing pulse generator such as a 316 or a reflective sensor (see FIG. 8). 317 is an operation panel provided with a numeric keypad, etc.; 318 is a display unit for displaying various types of information (see FIG. 1); 319 is a circuit for driving the motor and charger 19; and 320 is charger 14 and exposure device 15. , a circuit for operating the transfer charger 19, 321 a circuit for driving the paper feed roller 17 and a pair of transport rollers 18 for transporting the recording paper, 322 a jam detection circuit for detecting a jam of the recording paper, 323 a fixing device 20 324 is a circuit used to detect a sub-scanning synchronization error and a timing pulse error, and 325 is a circuit for detecting the end of toner in the developing device 16 and the end of recording paper in the paper feeding device 130.

The central processing unit CPU inputs input/output ports from each section 317, 322 to 325, etc. according to the program in the memory ROM.
4, performs interrupt processing using the sub-scan synchronization signal and timing pulse from the sub-scan synchronization detector 72 and timing pulse generator 314, and sends signals to each section 318 to 321, 323, etc. is output and sequence control is performed as follows.

1. Operation from power on to heater startup (Fig. 77)
1)).

When the main switch 2 is turned on, the main relay drive power source 308 is turned on. Furthermore, when the power switch 311 is turned on, the main relay drive power supply 308 activates the main flow drive system 309.
is energized. The stop position of the recording medium 11 when the power supply is stopped is at the position shown in FIG. 78 (1), and the invalid recording area (junction) X of the recording medium 11 is at a position where the recording area is adversely affected when the power supply is stopped.

That is, in this example, the invalid recording area X is the charger 14.
It is stopped below the curvature part.

This is because ozone is generated by the charger 14 during the image forming operation, and if the recording medium 11 is stopped for a long time, it is undesirable for the recording area to be adversely affected by the ozone. In FIG. 78, y and z indicate the leading edge of the image (recording start position) on the recording medium 11 and the position of the sub-scanning synchronization mark 71 (see FIG. 8). When the control system power supply 310 is turned on,
The central processing unit CPU starts operating, and first the memory RAM
is cleared, each input/output port is set, the output system is set, and the stack pointer SP is determined. Each flip-flop and timing pulse counter T are included in the memory RAM.
PCOU, set counter (the number of prints is set) 5ETCOU etc. are programmed in advance.
specified. Next, the heater 4 is set, the fuser control circuit 323 turns on the heater 207 of the fixing device 20, TPCOU is cleared, the interrupt INTI (interrupt by timing pulse) mask is reset, and the interrupt I
Set the mask for NT2 (interruption caused by sub-scanning synchronization mark detection signal). When the heater 207 reaches the set temperature, it is turned off by the fixing device control circuit 323. The central processing unit CPU confirms that the heater 207 is turned off based on a signal from the fixing device control circuit 323, and then turns the motor and static eliminator 2 off.
Turn on 1. When the motor 273 starts to rotate, the timing number (i) TPCOU counts up due to an interrupt from the Lux TP, and when the number reaches the set number N, the motor 2
73 and the static eliminator 21 are turned off, the heater 4 is reset, and the lNTl mask is set. When the motor stops, the recording medium 11 moves to the position shown in FIG. 78 (2), and the invalid recording area X stops immediately before the driven roller 12 on the upstream side of the static eliminator 21. Note that there is a possibility that noise etc. may enter the manual system of the sub-scanning synchronization mark detection signal while the motor is rotating, so to prevent this, a mask of INT2 is set.

2. Operation of the main routine Although the main routine is not shown in detail in FIG.
/busy) display 1, recording paper end display, toner end display, jam display in paper feeding and transport system, etc., sub-scan synchronization error display, timing pulse error display, thermistor disconnection display, collected toner display, etc. Run the program.

In the error check, sub-scanning synchronization errors and timing pulse errors are checked while the recording medium 11 is rotating. Here, the sub-scanning synchronization mark 2 on the recording body 11 is detected by the detector 72, but if the sub-scanning synchronization mark is not detected within a predetermined time period that is slightly longer than the time for the recording body 11 to rotate once, the sub-scanning synchronization mark 2 is detected by the detector 72. It is determined to be a sub-scanning synchronization error. Further, the timing pulse generator 314 generates timing pulses by rotating the recording body 11, but a timer with a time longer than the regular time of the pulse interval is provided, and the timing pulses are no longer generated at intervals within the timer time. Sometimes it is determined to be a timing pulse error. Fuser control circuit 32
In the thermistor disconnection check in step 3, if the thermistor is disconnected while the printer is in standby mode, a disconnection is immediately displayed and the printer enters a busy state, but if the thermistor disconnection occurs while a process is in progress, the running process ends. Busy at this point.

Here, a part of the fixing device control circuit 323 is shown in FIG.

In the figure, TH is a thermistor, TP is a temperature fuse provided in the fixing device 20, TRI is a transistor, OPI is a converter, and R1 to R7 are resistors. Thermistor T)I
Detects the temperature of the fixing device 20, and has a characteristic that the resistance value is high at low temperatures and decreases at high temperatures. Comparator OPI compares the potentials of point A and point B,
The output is used to turn on and off the heater 207 of the fixing device 20. When the thermistor TH is disconnected, the transistor TRI is turned off and a high level output is output to the central processing unit CPU.

The presence or absence of recording paper is detected by a paper end sensor 133 included in the circuit 325, and when the recording paper runs out, the sensor 133 outputs a paper out signal. In this way, the central processing unit C
PU sets print z (P l/F) in memory RAM to 0
By setting the last paper F/F (RP F/P) to 1 and setting the end/(E/p) to 1, the display unit 318 displays the end of the recording paper, and the process is started from the last paper. It is stopped when the recording paper has finished coming out to the recording receiver IO.

As can be understood from the time chart of FIG. 81 and the flowchart of FIG. 77 (6), the paper feed and conveyance system jam check is performed using a fixed count value of timing pulses. If there is a paper feeding error, the heater and process are turned off and the write enable signal WRE is set to 0. Therefore, since the motor is not stopped, it will stop after the paper ejection in the previous process is completed. If the recording paper jams during transportation, there is a risk that the recording paper will get into the fixing device 20 or the transportation system, so immediately turn off the motor, heater, and process when the jam is detected.

Also, in the event of a paper feeding error or paper jam, the display unit 318 will naturally display the error. Paper feeding error detection and jam detection will be described in detail later.

The manual operation of the key checks printing input, number of print input, etc. from the operation panel 317.

Therefore, in the main routine, the above-mentioned operations are repeatedly performed at times other than interrupt operations.

3. Operation when power is turned off (see FIG. 77 (3)) This operation is inserted as part of the error check routine.

First, it is checked whether the motor is off, and if the motor is off, it is checked whether the power switch 311 is turned off. When the power switch 311 is on, the central processing unit CPU receives a low level input.
When the power switch 311 is off, a high level input is input. If the power switch is off, the timing pulse counter TPCOU is cleared, the heater is turned off, the motor is turned on, and the mask of lNTl is reset.
Set the second mask. When the motor rotates, timing pulses TP are counted by TPCOU, and when the value reaches the set value M, the motor is turned off, and after a slight delay time, the transistor 313 is turned off. Main relay 307 is turned off, and AC drive system 309 and control system power supply 310 are turned off. At this time, the recording body 11 is shown in FIG.
It will stop at the position shown in 1).

4 Print start operation (see Fig. 77 (4)) When the print key on the operation panel 317 is turned on, it is determined by the key check routine, PF/F is set, and RPF/P and E/ are turned on. Set to 0. 5 more ET
It is sufficient if some COU are set by checking COU, but if it is 0, set 5ETCOU to 1. Next, the mask of INT1 is selected and the mask of INT2 is reset.Finally, the motor 273 and the static eliminator 21 are turned on.

5. Operation of INT2 by sub-scanning synchronization signal (Fig. 77 (
(See 5)) When the sub-scanning synchronization signal is input from the detector 72, the INT
2(7) Execute the routine. First, the block 1NTl is set to prohibit interrupts caused by timing pulses, and after a slight delay time, it is checked whether or not there is still a sub-scanning synchronizing signal.

If there is no mask, reset the mask of lNTl and return. This sub-scanning synchronization signal is checked in consideration of the case where there are scratches, dust, etc. on the recording medium 11 other than the marks. Therefore, even if the mark is detected once by the detector 72, if it is not detected at the next check, it is determined that the mark is not a regular mark, and malfunctions can be prevented. If the mark is judged to be genuine, turn TPCOU to O and RP.
Check whether / is standing. If R
If P' and + are not set, check 5ETCOU. When RP / is standing, E / F is raised and IN
Set the T2 mask. Go to the routine that checks 5ETCOU and sets a mask of 0 and 7'j RAINT2.

If 5ETCOU is O, set RP / and TN
Set the T2 mask. After setting the mask of INT2, the mask of 1NT1 is reset and the routine returns to the interrupt routine. Regarding the synchronization signal detection circuit,
Although shown in FIG. 82, details will be described later.

6. Operation of lNTl by timing pulse (77th
(See FIG. 6 and FIG. 81) When a timing pulse is input, it is counted by TPCOU and each process is controlled.

(1) When the print key on the operation panel 317 is input manually, the lNTl mark is set until the sub-scanning synchronization mark is detected by the detector 72.
TPCOU does not operate (as described in the explanation of print start operation). Also, P/F is 1.

(2) When the motor rotates and the sub-scan synchronization mark is detected by the detector 72, TPCOU is set to 0 and INT2
and reset the mask of lNTl. Therefore, from now on, every time a timing pulse is input, TPCOU
is added up. Also, the mask of INT2 is TPCOD
Set until it reaches a predetermined value (here L),
Interruptions caused by mark detection signals from the detector 72 are prohibited to prevent scratches on the recording medium 11.

Prevents mark detection signals caused by dust, etc.

(3) Add timing pulses by T P COD, check whether the heater % is 0, and if it is O, turn off the charger 14 when TPCOU reaches the set value A. If the heater 4 is 1, a power-on routine is entered.

+41 When TPCOU reaches set value B, turn WRE to O.
shall be. This is meaningless since WRE is not originally set when printing starts.

+51 When TPCOU reaches the set value l, the charger 14 is turned on.

[61T When COU reaches the set value J, set WRE to 1.
Then, an externally provided timer TM is started. As shown in FIG. 80, this timer TM receives WRE through a differentiating circuit comprising an inverter Nl, a capacitor C1, and a resistor R8.

In FIG. 80, F1 to F4 are flip-flops, N,
~N5 inverter, C1~Cttd capacitor, R8
-R14 is a resistance, A! ~A3 is the gate, DR,, DR2
is a driver, 'MC is a transport latch that drives the transport system (indicated by reference numeral 299 in Fig. 4), and MC2 is a paper feed roller 6α.
A paper feed clutch (indicated by reference numeral 304 in FIG. 4) that drives the
It is. The flip-flop F1 is reset by WREK and is reset by the detection signal from the registration sensor 179 (see FIG. 2), and the clip-flop F2 is set by the detection signal from the registration sensor 179 and output from the paper discharge sensor 272 (see FIG. 61). ) is reset by the detection signal from The registration sensor 179 is connected to the transport roller pair 1
The recording paper is detected at point 8, and the paper discharge sensor 272 detects the recording paper at the paper discharge port. The central processing unit CPU has a flip-flop F1. The output of F'2 is checked at a predetermined timing to determine a paper feeding error or conveyance jam.

(7)■, When TPCOU reaches the set value C, F 5YN
C (signal representing the image width sent from the outside) is checked, and if it is 1 and there is no conveyance jam, return.

(2) If F8YNC is not 1, WRE is set to 0 and the charger 14 is turned off.

Check the conveyance jam with ■, @ or
is set, it is determined that there is a conveyance jam, the conveyance jam % is set to 1, the charging charger 14 and the transfer charger 19 are turned off, and the display section 318 is made to display this.

(8)■, When TPCOU reaches the set value, SE'rC
If OU is O (RPF/F is O, output the paper feed signal and conveyance signal, select flip-flops F3 and F4, turn on the conveyance latch MCI and paper feed clutch MC2, and
Decrease ETCOU by 1. Next, 5ETCOU is R instead of O
If PF/F is 0, return.

■, 5ETCOU becomes 0 after deducting 5ETCOU by 1 with @.
If Deteri RPP/F is 1, it will be 9%, then return with 0.

■, 5ETCOU becomes 0 after deducting 5ETCOU by 1 with @.
If so, set PP/F to 0 and return.

■, 5ETCOU is 0 (If RP F/F is 1, then 9
Set the % to 0 and return.

(2) If 5ETCOU is 0, the charger 14 is turned on.

(When paper 91 reaches the registration sensor 179, the clip-flops F3 and F4 are reset, and the paper feed clutch MC2 and conveyance latch MCI are turned off.

(10) When TPCOU reaches the set value E, the paper feed signal is turned off, a reset signal is given to the flip-flop F4, and the paper feed clutch MC2 is turned off.

(11) When TPCOU reaches the set value F, the paper feed jam is checked, and if the paper has not reached the registration sensor and the flip-flop F is set, it is determined that there is a paper feed error, and the paper feed jam is changed from 4 to 1. and charger 1
4. Turn off the transfer charger 19, paper feed clutch MC2, and conveyance latch MCI, and display a jam message on the display unit 318.

(12) When TPCOU reaches the set value G, the transfer charger 19 is turned off.

(13) When TPCOU reaches the set value K, the transfer charger 19 is turned on.

(14) When TPCOU goes low, reset the mask of lNT2.

(15) When TPCOU becomes H, Rj/, E/
is 1, all processes including the rotation of the motor 273 are turned off, and lNT1. Set the mask for lNT2.

Here, the stop position of the recording medium 11 is the same as at the time of printing start.

The time chart in FIG. 81 is an example when recording two sheets.

■ If P' is 1, the above operations (1) to (14) are performed, but when RP% is 1, paper feed clutch MC2, conveyance latch MCI, charger 14, and transfer charger 1 are activated.
9 does not turn on.

■ If RP '4 and 8% are 1, only operation (15) is performed.

However, during the operations of (1) and (2), there is no problem even if the other cheek and off operations are performed.

In this example, when recording is performed on only one sheet, the recording medium 11 rotates three times.

As described above, according to the present invention, the recording body stop position when recording is possible is set upstream of the reusable process and as close as possible to this reusable process, so that When the time is short and recording is possible, the amount of rotation of the recording medium after recording is completed is also small. In addition, since it is dangerous to start the reusability process halfway, the recording medium can always be reused under the same conditions, resulting in a good recording medium.

In addition, the joint part X of the recording body 11 included in the recording invalid area is
It has an uneven shape that is different from other parts of the recording medium,
It is not desirable to stop it at the curvature portions E and El (see FIG. 22) of the recording medium because it is weak in strength and the light guide layer etc. are likely to peel off. In this respect, in the present invention, since the joining portion is stopped in a linear region, no force is applied in a direction that weakens the joining portion of the recording medium, so that the mechanical strength of the recording medium can be maintained for a long period of time.

An example of the synchronization signal detection method will be explained based on FIG. 82 and FIG. 83.

In the synchronization signal detection circuit SDA in FIG.
．． A2 is an AND circuit, MMI and MM2 are monostable multiviprator, INVI and INV2 are inverters, and the operation of this synchronization signal detection circuit SDA is shown in Fig. 83 (
This will be clear by referring to the waveform diagrams of the signals shown in figures α) to (A), and the outline thereof will be explained next.

If the output signal of the detector 72 (FIG. 83(a)) is given as the other input of the AND circuit Al, and a signal of level 11 is given as the other input from the inverter ■Nv2, which will be described later, then the AND circuit A1 There is a pulse p on the output side of
s is output. The monostable multivibrator MMI, which is triggered by the rising edge of the pulse P appearing on the output side of the AND circuit A, generates a pulse PrrL1 (Fig. (h) Figure) is output.

The pulse pml is converted into a pulse PrLl (FIG. 83(C)) whose polarity is inverted by the inverter INV, and is applied as one input of the AND circuit A2. On the other hand, as the other input of the AND circuit A2,
Since the output of the AND circuit AI mentioned above is given,
If the signal output from the AND circuit AI has a pulse width longer than the output pulse (τm) of the monostable multivibrator MMI, the 83
The pulse pst is output as shown in FIG.

If the signal output from the detector 72 is not the synchronization signal P9, that is, if it is noise, the pulse width of the pulse due to the noise is significantly shorter than the pulse width τ of the synchronization signal. The output noise pulse is not output from the AND circuit A2, and the output pulse pst from the AND circuit A2 is given to the CPU as a true synchronization signal.

By the way, when the printer is performing continuous recording operation, the recording medium 11 is moving at a constant speed, so the synchronization signal in this state appears at constant time intervals T.

Therefore, when the true synchronization signal is detected from the AND circuit A2, the period T of the synchronization signal described above is based on that point in time.
By creating a gate signal with a pulse width of time T2, which is slightly shorter than , and applying it to the AND circuit Al, the synchronization signal can be detected more accurately.

In FIG. 82, the above operation is performed by the output pulse pst of the AND circuit A2, and the monostable multivibrator MM2 receives the output pulse pst of the AND circuit A2.
It is triggered at the falling edge of st and outputs a pulse Pm2 (Fig. 83(e)) with a pulse width T2 slightly shorter than the period TI of the synchronizing signal to the output side, which is gated by the inverter INV2. This is done by making the pulse PW2 (Fig. 83) and giving it to the AND circuit A as a gate signal.

It will be understood that according to the detection method described above, a true synchronization signal can be detected from the output signal of Φ from the detector 72 and provided to the control section.

Furthermore, the printer of the present invention has safety measures in place in the event of a trouble in conveying the recording paper, such as a paper feeding error or a jam, and safety measures with simplified control are provided.

Such safety means include a paper end sensor 133 that detects the presence or absence of recording paper in the recording paper tray 3. ! :,paper"
a write enable that outputs a signal to cause the recording paper to be fed only when the signal "Yes" is output;
A registration sensor 179 is arranged behind the pair of transport rollers 18 and detects whether or not there is a recording paper at this position when the recording paper is fed out by the paper feed roller 17; The registration sensor 272 (61st
(see figure), and when the recording paper is detected by the registration sensor 179 after the write enable signal is issued,
A register that outputs the following signals: "Paper feeding successful", "Paper feeding failed" when the registration sensor 179 does not detect recording paper, and "Paper feeding successful" when no write enable signal is generated, regardless of the state of the registration sensor 179. When the error detection means and the registration sensor 179 detect that the recording paper is present, and the paper ejection sensor 272 detects that the paper is present, there is no jam, and the paper ejection sensor 272 detects that the paper is present. If the registration sensor 179 detects no recording paper, it outputs a "jam" signal, and when the registration sensor 179 detects no paper, it outputs a "no jam" signal regardless of the state of the paper ejection sensor 272. End sensor 133. Registration error detection means.

Regardless of the state of the jam detection means, the capturing operation is always performed at a predetermined timing as the process progresses.

Now, in Fig. 84, the motor does not start.
(see figure (a)), when the synchronization signal is input (see figure 84 (
h)), the process control proceeds based on this, and after inputting the synchronization signal, the paper end output is captured at the timing tl (see Figure 84 (-1)), and the jam detection output is captured at the timing t2 (see Fig. 84 (-1)). Figure 84 (λ) agglutination), t
Incorporating the paper feed error at the timing of step 3 (Fig. 84 (&)
(see FIG. 76) is executed by the CPU (see FIG. 76).

The write enable signal is output after it is detected that the paper is not at the end (see FIG. 84(C)), and then the paper feed drive system is operated. The flip-flop circuit F/Fl is set at the rising edge of the write enable (see FIG. 84(t)), and is reset at the rising edge of the registration sensor 179 (see FIG. 84(y)).
Figure 84 (see il). In other words, when the sensor 179 rises, it is determined that the paper feeding has been successful, and when there is no rise, it is assumed that the paper feeding has failed, the paper feeding drive system is stopped, and the heater 2o7 (
(see Fig. 61) is turned off, the preceding recording paper is ejected from the machine, the motor is stopped, and a paper feeding error is displayed. If the write enable is not output, the flip-flop circuit F/Fl will not be set, so in this case,
It is determined that the paper feeding was successful. Flip-flop circuit F/
F2 is set at the startup of the registration sensor ]79 (
(see FIG. 84 (U)), and is reset at the falling edge of the paper discharge sensor 272 (see FIG. 61) (see FIG. 84 (A)).
(See Figure 84(j)). That is, after a successful paper feed,
By the timing t2 of the next cycle, the paper ejection sensor 27
If there is a rise of 2, it is determined that there is no jam, and if there is a rise, it is determined that there is a jam, the heater 207 is turned off, the entire drive system is stopped, and a jam is displayed. In addition, in the case of paper feeding failure, the clip-flop circuit F/F2
is not set, no jam is detected during the ejection operation of the preceding recording paper.

Fig. 85 shows a time chart when the paper end is detected, but this is the case when the Hoech end is detected in the second cycle, and when the paper end is detected (see T1 in Fig. 85). , the write enable signal is not output and the paper feed drive system does not operate. Therefore, the clip-flop circuit F/Fl is not set, and even if a signal for detecting a paper feeding error is captured, it is considered that the paper feeding is successful. Further, since the transfer material is not supplied to the registration sensor 179, the flip-flop circuit F/F2 is also not sent, and even if a jam detection operation is performed, it is determined that there is no jam.

Note that the paper end is detected at the right time here, but it is detected before the signal indicating that the paper feeding operation is about to be performed (in this case, before the write enable is output). It would be good if it were done.

Fig. 86 shows a time chart when a paper feeding error occurs. This is a time chart when a paper feeding error occurs in the second cycle. T
2), the Him detection operation is carried out to prevent danger, but in case of a paper feeding error, the flip-flop circuit F/F2 is not set, so the operation shown in FIG. 87 is performed using a microcomputer or the like.

As is clear from the above description, according to the present invention, an Al 2.

In both blocks A2+ B and C, tl,
Since the operation of increasing each output is performed at the timings of t2 and t3, control can be easily performed. Further, there is no need to prevent subsequent detection operations due to paper end, paper feeding errors, etc., and there are advantages such as simplified control.

Conventionally, image forming apparatuses have safety devices that include a paper second sensor that detects the presence or absence of recording paper, a registration sensor that detects paper feeding errors, and a jam sensor that detects jams. We are taking appropriate measures. For example, if the paper end sensor detects that there is no recording paper, the system does not feed the recording paper, and at the same time prevents the registration sensor and jam sensor from detecting the paper to prevent the device from going into an abnormal state. There is.

Further, when a paper feeding error is detected by the registration sensor, the detection operation of the jam sensor and its safety measures are blocked to prevent the apparatus from going into an abnormal state. However, in a printer using an endless belt-shaped recording medium, sequence control must be performed based on a synchronization signal, and in the case of paper end, paper feeding error, etc., in the conventional technology, Since the detection operation is prevented, separate sequence operations are required for each case, which has the disadvantage of complicating control.

When the motor starts, a rotation period signal is generated once per rotation of the recording medium to synchronize the recording medium and the sequence. After a certain period of time after the first synchronization signal is input, a write enable signal, that is, a signal indicating that an image may be written is output. Then, the paper feed roller is driven to feed the recording paper.

When the recording paper reaches the registration sensor, the drive of the paper feed roller and the conveyance roller is stopped, and the recording paper is made to stand by at a predetermined position.

Next, the conveyance roller is restarted in response to a timer signal indicating that a predetermined time has elapsed since the output of the write enable signal, and the leading edge of the image and the leading edge of the recording paper are aligned. However, in this case, there is a block that only detects paper feeding errors (AI), a block that detects both paper feeding errors and jams (A2), a block that only detects jams (B), and a block that does not perform any detection operation (C). ) must be controlled separately, and although it would be easier to control if each block had more common features, it had the drawback of becoming more complex. In addition, in conventional devices, for example, if the paper end is detected in block (A2) and no paper feeding operation is performed, it is necessary to prevent the paper feeding error detection, and the paper feeding error is detected. If so, a block (
In B), there were drawbacks such as the need to prevent jam detection and safety measures based on the jam detection.

In the present invention, AI, A2. It will be understood that since both blocks B and C input the outputs of the respective sensors at predetermined timings, control can be performed extremely easily.

The temperature of the heater in the fixing device is detected by a thermistor, and the power is controlled to maintain a constant temperature. Conventionally, a temperature fuse is inserted in the heater current loop because there is a risk that the heater will overheat if the thermistor is disconnected or an abnormality occurs in the temperature detection circuit including the thermistor.

Furthermore, when the thermistor is disconnected, a potential rise or potential drop due to the thermistor disconnection is detected.

Therefore, when the thermistor is disconnected, an abnormality is immediately and automatically detected. However, if the temperature fuse blows, it will remain as it is. Some copiers start counting time from the time the heater power is turned on, and if the temperature detected by the thermistor does not reach a predetermined value or higher within a predetermined time, it automatically determines that there is an abnormality in the power system, including a temperature heater meltdown. There is a loss time because the determination is made after the heater temperature rise time when it is normal after the power is turned on and the heater power is turned on. Further, normally, this abnormality determination flow is executed only immediately after the device power is turned on, and if the temperature fuse blows after the temperature once rises, it remains as it is. To prevent this, we have created an abnormality detection flow that monitors the heater energization time, de-energization time, etc., and determines that the heater power system is abnormal if the thermistor-detected temperature is less than a predetermined value at a time when the temperature should naturally be above a predetermined temperature. It must be included in the copy sequence, detection of abnormalities in the heater power system is not complicated, and there are many tasks to be processed in the print sequence.

The present invention includes a temperature detection circuit that can detect abnormalities in the heater power system, including thermistor disconnection, early and easily, and at the same signal level with one line. This circuit connects a thermistor in series with a temperature-responsive element such as a temperature fuse or thermoswitch that becomes electrically open above a predetermined temperature, and at least one resistor, which is connected between constant voltage terminals. A temperature responsive element is arranged in a temperature sensing area of the fixing heater, one end of the thermistor is used as a temperature sensing end, and a connection point between the series circuit of the thermistor and the temperature responsive element and the resistor is used as an abnormality sensing end. According to this, the disconnection of the thermistor and/or the temperature responsive element end becomes the potential of one of the constant voltage terminals.

In addition, in printers, the power to the control device and other side elements of the machine are turned on by turning on the so-called power switch for operator operation, or by closing the power relay switch in response to an external ON instruction signal. The control device sets each section to a print standby state. Therefore, each part is in a predetermined state when printing starts, and printing starts smoothly. When printing is completed, the printer returns to the front standby state, so it is preferable that the power is cut off in the standby state by turning off the power switch by an operator's operation or by opening a power relay switch due to disappearance of an external ON instruction signal. However, if the power is cut off during print processing, the printer may malfunction the next time the power is turned on due to unejected recording paper, insufficient cleaning, etc., and copy quality may deteriorate. Particularly in the case of a recording medium, ozone generated by the charger may remain in the charger case, causing deterioration of the surface of the recording medium in the image forming section, resulting in poor latent image quality from the next time onward.

The present invention includes means for cutting off the power after performing desired processing in the printer itself, and for cutting off the power after removing the image forming section of the recording medium from the charger area.

This means inserts a power supply connection device between a commercial AC power source and a power receiving side including a recording processing control DC power supply device, and further includes a power supply means for supplying power from the commercial AC power source to the power receiving side. The power supply connection device is set to "on" when the power supply means is turned on, and when the power supply means enters the power supply cutoff state, the power supply connection device is set to "off" after completion of a predetermined action of the recording processing mechanism. It has become.

Further, a sub-scanning synchronization mark 71 is attached to the recording body 11, and a synchronization mark detector is provided in the drive system of the recording body, and a detection pulse, that is, a timing pulse synchronized with the movement of the recording body, based on mark detection. is counted, and the timing of print processing such as paper feeding, charging, exposure, transfer, etc. is determined based on this count value. Since the recording medium may slip with respect to the driving roller, the count value is initialized to a predetermined value K (usually clear and zero) every time a mark is detected.

However, if the amount of slip is large, print processing timing shifts such as image shifts occur, and these cannot be prevented by initialization alone. Conventionally, a timer is triggered when a mark is detected, and if the mark is not detected immediately after the timer times out, a timing error has occurred and a display device is activated to indicate the need for inspection to notify an abnormality. I try to do it. However, in conventional error detection of this kind, a hardware timer (time limit circuit or timer IC) is connected to the central control unit 7 that controls the timing of the print processor steps, which increases the cost and sets the time limit. An adjustment circuit is required to cover errors in C and R (element errors), and adjustment work is required.

In addition, since the time limit shifts depending on the temperature, it is necessary to set it to a certain point, and the slip abnormality detection becomes rougher accordingly.

The printer of the present invention is capable of reliably detecting timing errors with a low-cost configuration without using analog time-limiting circuits, elements, etc.

That is, by focusing on the timing pulse count value from mark detection, which determines the print timing, a timing error is detected when the timing pulse count value exceeds a predetermined value, which is slightly higher than the predetermined belt feed count value between mark detections. do. That is, the central control unit for print processing timing control performs timing pulse counting processing itself and detects sheller through digital processing. This eliminates the need for an external timer, and c, Ry
Error detection is performed almost unaffected by 4-difference temperature fluctuations.

Further, the timing when the recording medium slips with respect to the drive roller is not constant, and the phase difference between mark detection and timing pulse generation is not constant.

In some cases, a timing pulse appears during mark detection, and in other cases, a timing pulse appears just before or after mark detection. (The relative deviation between the initial value of the timing pulse count and the position of the recording body) differs for each initialization, which results in a deviation in print processing timing including image deviation.

The present invention prevents such positional shift fluctuations when the timing pulse count is set to +71.

That is, in the present invention, when detecting a mark, the timing pulse count value cT is compared with the standard value Q, and the deviation CTQ between them is set as the initial value of the timing pulse count. For example, if the timing pulse count value cT = Q-1 at the time of mark detection, the timing pulse appeared immediately after the mark detection in the previous initialization (the previous processing timing was one timing pulse with respect to the belt position). The current initial value is set to -1, and the current processing timing is delayed by l timing pulses relative to the belt position compared to the previous time. Considering that a timing pulse appeared just before mark detection during initialization (the previous processing timing was delayed by one timing pulse with respect to the belt position), the current initial value was increased by +1.
, the current processing timing is delayed by +1 timing pulse compared to the previous time, and when CT""Q, it is assumed that the belt position and processing timing match, and the initial value is set to 0.

Conventionally, if a timing pulse came while the lNTl mask was being inserted, that pulse would be ignored, and the image width (
(sub-scanning) becomes inconsistent. The actual image width is the set timing pulse number (count value J-+B in the timing chart), so if TP-COU is set to 0 during this count number, the count number at J-+B4 will be O±1. This will cause a counting error. Therefore, in this embodiment, the above consideration is taken, and before setting the TP-COU, the count value of the TP-COU up to now is recorded on the recording medium 11.
Number of timing pulses required for one rotation (number constant Q)
Compared to Q-1, TP-COU is set to FF and Q
If +l, set TP-COU to 1; if other than Q±1, set TP-COU to o (Here, assume that TP@COU is composed of 8 pintos and is expressed in hexadecimal)
Set to . Therefore, if the time obtained by adding the number of execution instructions of the delay time 7 INT2 is made almost the same as the time of the timing pulse width, the image (print) width will be almost constant. Even if it deviates, it will be within the conventional 5. Here, since TP-Co is 0 at the start, the contents of TP-COU are not changed. Although the initial value is set to 0, it goes without saying that there is no need to stick to 0. Also, the timing pulse error is o:Il:
1, but it is not limited to this; for example, 0 and 5 can be used to process it with a program.

In the print control flow, when the belt 1 is driven, slip may occur between the driving roller, the driven roller, and the recording medium 11. If there is a slip, the image recording position and invalid recording area will be exposed, and the operation of each process will be delayed, causing image disturbance. Therefore, a number Cp, which is slightly larger than the number of timing pulses required for one rotation of the recording medium, is set in the program that executes this flow, and the sub-scanning synchronization signal is sensed (INT2
), it is fine as long as the recording medium 11 and the roller are in close contact with each other normally, but during use, flakes, toner, etc. may get into the space and cause slips, causing the regular timing pulse to be counted too many times. When the count reaches the set value P, the sub-scanning error F7'p is set to 1. In a normal driving state, a mark is detected by the P count and the counter is initialized, so the sub-scanning error F/F is not set.

When the sub-scanning error F/F is set to 1 at P count, the energization of each mechanism is stopped because the sub-scanning error F/F has been sected in the error check flow shown in Fig. 77 (3) D. , displays an error.

Next, the configurations of different examples of the power supply section are shown in FIGS. 90 and 91.
As shown in the figure. In the one shown in FIG. 90, the power source means is a PNP power transistor circuit 332, which is connected to the coil of the main relay 307, and the circuit 332 is turned on by an external power-on signal, and the main relay 3
07 is set to close.

A power-on signal from the outside is applied to the input port of R<)M, and the CPU monitors it and performs print processing and opening/closing control of the main relay 307 in the same manner as in the previous embodiment. Furthermore, when the power can be turned on by an operator operation, a power switch 311 is connected in parallel to the circuits 313 and 332. In the one shown in FIG. 91, in order to eliminate power consumption in the AC/DC conversion circuit 308 when the power is turned off, the circuit 308 is omitted, and a bipolar power switch 333 is connected in parallel to the relay 307 instead. According to this, the power switch 333 is open, there is no external power-on instruction, and the CPU is connected to the switching circuit 313.
When it is turned off, there is no power consumption at all, and security measures are reduced accordingly.

[Brief explanation of the drawing]

Fig. 1 is an external perspective view showing an example of the printer according to the present invention, Fig. 2 is a schematic side view showing the internal structure of the same, Fig. 3 is a side view showing the drive system of the above, and Fig. 4 is the same as the above. A schematic plan view, FIG. 5 is an exploded side view showing a recording medium/developing unit consisting of a recording medium unit and a developing unit, and FIG. 6 is a perspective view of essential parts showing an example of means for applying tension to the recording medium. FIG. 7 is a perspective view of the recording medium/developing unit, showing the state in which the recording medium unit is positioned and installed in the recording medium moving direction with respect to the developing device unit, and FIG. 8 is the state in which it is installed in the main body of the apparatus. 9 is a schematic side view showing the recording medium/developing unit positioned vertically with respect to the printer body; FIG. 10 is a schematic plan view of the same; FIG. FIG. 11 is a front view showing the positioning mechanism of the recording unit in the width direction of the recording body, FIG. 12 is a plan view of the same, and FIG. 13 is a schematic side view showing an example of the driving means of the recording body/developing unit. Fig. 14 is a perspective view of the same as above, Fig. 15 is a perspective view showing an example of the recording medium tension release mechanism, Fig. 16 is a side view of the same as above, Fig. 17 is an operational view of Fig. 16, and Fig. 18 is release mechanism. A perspective view showing another example of the lever, FIG. 19 is a perspective view of a main part showing a receiving part provided with a positioning means for a recording unit, FIG. 20 is an enlarged plan view showing an example of a belt drift detection means, FIG. 21 is a sectional view showing the photointerrupter;
The figure is a side view showing the curvature area and the straight line area of the endless belt-shaped recording medium, FIG. 23 is an enlarged plan view showing another example of the belt deviation detection means, and FIGS. 24 and 25 are respectively the belt deviation detection means. A plan view showing another example, FIG. 26 is a diagram illustrating another example of the belt deviation detection means and the principle operation of the deviation control means, FIG. 27 is a front view of FIG. 26, and FIG. Figure 29 is a front view showing still another example of the belt deviation detection means; Figure 30 is the output of the reflective optical sensor shown in Figure 29. Fig. 31 showing signal changes is a perspective view showing yet another example of the deviation detecting means, Fig. 32 is a perspective view showing an example of the deviation controlling means, and Fig. 33 shows the deviation detecting means and the deviation controlling means. 34 is a side sectional view showing an example of the developing device, FIG. 35 is a partial rear view of the developing device, and FIGS. 36 to 39 are 40 is a side sectional view showing an example of the maintenance operation mechanism for the recording medium/developer unit; FIG. 41 is an operational view of the same; FIG. 42 is the maintenance operation mechanism A plan view of the main parts showing another example, Fig. 43 is an operational view of the same as above, Fig. 44 is a side view of the main parts of the paper feeder with the side plate of the recording paper tray removed, and Fig. 45 is an operational view of the same as above. , Fig. 46 is a perspective view of the main parts of the same as above, Fig. 47 is a side view showing another example of the paper reset mechanism, Fig. 48 is an operational view of the same as above, Fig. 49 is a perspective view of the same as above, Fig. 50 is 51 and 52 are side views showing the operating state of the recording paper sensor; FIG. 53 is a side sectional view showing an example of the recording paper guide cover; and FIG. 54 is a front view of the same. , FIG. 55 is a side sectional view of the main part showing different examples of the guide cover, FIGS. 56 and 57 are side views showing different examples of the guide cup (-), FIG. 58 is a front view of the second stirring member, FIG. 59 is a side view of the mechanism for reciprocating the second stirring member, FIG. 60 is a front view showing another example of the second stirring member, and FIG.
62 is a side sectional view showing the function of the fixing device and a different example of the paper ejecting means. FIG. 63 is a side view showing the cleaning mechanism. FIG. 64 is a side sectional view showing the fixing device and paper ejecting means. A perspective view of the same as above, FIG. 65 is a perspective view of the paper discharge unit, FIG. 66 is a front view of the paper discharge roller, FIG. 67 is a side view of main parts of the cleaning device, and FIGS. 68 and 69. 70 is a side sectional view showing different cross-sectional shapes of the opposing member, FIGS. 71 and 72 are side views showing different examples of the opposing member, 73 74 and 75 are side views showing further different examples of the opposing member, respectively. FIG. 76 is a block diagram showing the sequence control section of the apparatus of the present invention. Fig. 77 is a flowchart showing the sequence control as above, Fig. 78 is a diagram showing the recording body stop position when power supply is stopped and when recording is possible, Fig. 79 and Fig. 80 show a part of the circuit of this device. FIG. 81 is a time chart of the device of the present invention, FIG. 82 is a block diagram showing an example of a synchronization signal detection method, FIG. 83 is a time chart of the same as above, and FIGS. 84 to 86 are time charts for recording paper detection. Figure 87 is the same flowchart as above; Figure 88 is a block diagram showing the detection and control of the recording body drift; Figure 89 is a time chart showing the timing of the drift control; Figures 90 and 91 are the power supply FIG. 4 is a circuit diagram showing different examples of each section. 3... Recording paper tray, 1o... Recording-paper tray,
DESCRIPTION OF SYMBOLS 11...Endless belt-shaped recording body, 12...Followed roller, 13...Drive roller, 14...
Charger, 15... Exposure device, 16...
Developing device, 17... Paper feed roller, 18... Registration roller pair, 19... Transfer charger, 2o...
- Fixing device, 21... Static eliminator, 22... Cleaning device, 24... Recording paper, 25... Paper discharge roller pair. P710 Eye damage 40 Figure Cloth 24 Figure) yfJz Cocoon sales Z & Grip σl Figure 483- 乃σ25 -484- 7H17f ll (A) (Z)
(δ) Steam 771D (47 (+5) Continued from page 1 0 Inventor: Ikeda Metropolitan Government Building, 1-3-6 Nakamagome, Ota-ku, Tokyo, Ricoh Co., Ltd. 0 Inventor: Shigeru Suzuki 1, Nakamagome, Ota-ku, Tokyo No. 3-6 Ricoh Co., Ltd. December 70, 1981 1 Case description 1981 Patent Application No. 165128 2 Name of the invention Printer 3 Person making the amendment Relationship to the case Patent applicant Location Tokyo 1-3-6 Nakamagome, Ota-ku Name (6)
74) Rico Co., Ltd.-4 Agent Address: 2-6-28-6 Sakuragaoka, Setagaya-ku, Tokyo 156
Contents of amendment (1) “Line” in line 18 of page 2 of the specification has been changed to “%”
Changed to σ-ㅅ. (2. Changed "mark" in line 9 of page 140 of the same document to "mask." (31 Changed [PNPJ to l MP
Changed to NJ. (Figures 90 and 91 of the attached drawings are replaced with those on separate sheets.

Claims (1)

[Claims] 1. A recording body unit including an endless belt-like recording body that is wound around a plurality of belt rollers and rotates in one direction; and a charging device that uniformly charges the recording body; an exposure means for forming an electrostatic latent image by irradiating a charged recording medium with optical information corresponding to a recorded image; and supplying a developer to the recording medium to visualize the electrostatic latent image. A developing unit including a developing roller, and a developing unit that includes a developing roller, and a recording paper in order to bring the recording paper into close contact with the recording medium on which the visible image has been formed.
A paper feeding device that separates and feeds the stacked recording paper one by one, a transfer device that transfers a visible image onto the recording paper that is in close contact with the recording medium, and a fixing device that fixes the visible image onto the recording paper. , already established.
A discharge device that discharges the recording paper to the outside of the machine; A static eliminator that removes the electric charge remaining on the recording medium after the visible image has been transferred; A cleaning device that removes developer from the sheet feeding device, a driving device that drives each device including the recording unit, and a control device that controls the operation of each device including the driving device. The recording paper that was ejected is
To be ejected out of the machine through a nearly straight recording paper path,
A printer comprising the above paper feeding device, recording unit, transfer device, and fixing device.